Search

A Japanese clinical trial (JGOG3016) showed that dose-dense weekly paclitaxel in combination with carboplatin extensively prolonged overall survival (OS) in patients with advanced ovarian cancer. However, in other clinical trials, dose-dense paclitaxel regimens were not superior to triweekly paclitaxel regimens. In this study, causal tree analysis was applied to explore subpopulations with different treatment effects of dose-dense paclitaxel in a data-driven approach. The 587 participants with stage II-IV ovarian cancer in the JGOG3016 trial were used for model development. The primary endpoint was treatment effect in terms of 3-year OS in patients receiving dose-dense vs. conventional paclitaxel therapies. In patients <50 years, the 3-year OS was similar in both groups; however, it was higher in the dose-dense group in patients ≥50 years. Dose-dense paclitaxel showed strong positive treatment effects in patients ≥50 years with stage II/III disease, BMI <23 kg/m 2 , non-CC/MC, and residual tumor ≥1 cm. In contrast, although there was no significant difference in OS; the 3-year OS rate was 23% lower in dose-dense paclitaxel than conventional paclitaxel in patients ≥60 years with stage IV cancer. Patients in this group had a particularly lower performance status than other groups. Our causal tree analysis suggested that poor prognosis groups represented by residual tumor tissue ≥1 cm benefit from dose-dense paclitaxel, whereas elderly patients with advanced disease and low-performance status are negatively impacted by dose-dense paclitaxel. These subpopulations will be of interest to future validation studies. Personalized treatments based on clinical features are expected to improve advanced ovarian cancer prognosis., (© 2024 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Background: Platinum/taxane (TC) chemotherapy with debulking surgery stays the mainstay of the treatment in ovarian cancer patients with peritoneal metastasis, and recently its novel modality, intraperitoneal carboplatin with dose-dense paclitaxel (ddTCip), was shown to have greater therapeutic impact. Nevertheless, the response varies among patients and consequent recurrence, or relapse often occurs. Discovery of therapeutic response predictor to ddTCip and/or TC therapy is eagerly awaited to improve the treatment outcome., Methods: Using datasets in 76 participants in our ddTCip study and published databases on patients received TC therapy, we first validated a total of 75 previously suggested markers, sought out more active biomarkers through the association analyses of genome-wide transcriptome and genotyping data with progression-free survival (PFS) and adverse events, and then developed multiplex statistical prediction models for PFS and toxicity by mainly using multiple regression analysis and the classification and regression tree (CART) algorithm., Results: The association analyses revealed that SPINK1 could be a possible biomarker of ddTCip efficacy, while ABCB1 rs1045642 and ERCC1 rs11615 would be a predictor of hematologic toxicity and peripheral neuropathy, respectively. Multiple regression analyses and CART algorithm finally provided a potent efficacy prediction model using 5 gene expression data and robust multiplex toxicity prediction models-CART models using a total of 4 genotype combinations and multiple regression models using 15 polymorphisms on 12 genes., Conclusion: Biomarkers and multiplex models composed here could work well in the response prediction of ddTCip and/or TC therapy, which might contribute to realize optimal selection of the key therapy., (© 2024. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)

Epithelial ovarian cancer (EOC) is widely recognized as the most lethal gynecological malignancy; however, its early-stage detection remains a considerable clinical challenge. To address this, we have introduced a new method, named Comprehensive Serum Glycopeptide Spectral Analysis (CSGSA), which detects early-stage cancer by combining glycan alterations in serum glycoproteins with tumor markers. We detected 1712 glycopeptides using liquid chromatography-mass spectrometry from the sera obtained from 564 patients with EOC and 1149 controls across 13 institutions. Furthermore, we used a convolutional neural network to analyze the expression patterns of the glycopeptides and tumor markers. Using this approach, we successfully differentiated early-stage EOC (Stage I) from non-EOC, with an area under the curve (AUC) of 0.924 in receiver operating characteristic (ROC) analysis. This method markedly outperforms conventional tumor markers, including cancer antigen 125 (CA125, 0.842) and human epididymis protein 4 (HE4, 0.717). Notably, our method exhibited remarkable efficacy in differentiating early-stage ovarian clear cell carcinoma from endometrioma, achieving a ROC-AUC of 0.808, outperforming CA125 (0.538) and HE4 (0.557). Our study presents a promising breakthrough in the early detection of EOC through the innovative CSGSA method. The integration of glycan alterations with cancer-related tumor markers has demonstrated exceptional diagnostic potential., (© 2024. The Author(s).)

Ovarian cancer, notable for its severe prognosis among gynecologic cancers, has seen substantial progress in treatment approaches recently. Enhanced protocols in chemotherapy and the introduction of poly (ADP-ribose) polymerase (PARP) inhibitors for maintenance therapy have markedly improved outcomes for patients with specific genetic profiles, such as those positive for BRCA mutations or exhibiting homologous recombination deficiency (HRD). Additionally, the method of intraperitoneal chemotherapy administration has emerged as a valuable alternative to traditional transvenous routes, showing promise for wider clinical adoption. The field of surgery has also evolved, with increasing exploration into the benefits and feasibility of laparoscopic methods over more invasive traditional surgeries, aiming for complete tumor removal but with reduced patient impact. The hereditary nature of ovarian cancer underscores the importance of genetic testing, which has become integral in tailoring treatment strategies, particularly in determining suitability for PARP inhibitors. The formation of the East Asian Gynecologic Oncology Trial Group (EAGOT) aims to optimize treatment across Japan, Korea, China, and Taiwan. The ovarian cancer committee of EAGOT shared the current policies, focusing on 5 topics: 1) strategies for maintenance therapy after initial surgery and chemotherapy, 2) drug regimens for platinum-sensitive and platinum-resistant recurrence, 3) intraperitoneal chemotherapy, 4) laparoscopic surgery as an alternative to laparotomy, and 5) current status of genetic testing (BRCA, HRD, and panel tests) for ovarian cancer and its prospects. EAGOT's multi-national trials aim to harmonize these evolving treatment strategies, ensuring that the latest and most effective protocols are accessible across the region, thereby significantly impacting patient outcomes in East Asia., Competing Interests: No potential conflict of interest relevant to this article was reported., (© 2024. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology, and Japan Society of Gynecologic Oncology.)

The Cancer Genome Atlas (TCGA) network has clarified that ~50% of high-grade serous ovarian cancers show homologous recombination deficiency (HRD). However, the frequency of HRD in Japanese patients with ovarian cancer remains unclear. We aimed to identify the frequency of HR-associated gene mutations in Japanese patients with ovarian cancer. The JGOG3025 study is a multicenter collaborative prospective observational study involving 65 study sites throughout Japan. We recruited 996 patients who were clinically diagnosed with ovarian cancer before surgery from March 2017 to March 2019, and 701 patients were eligible according to the criteria. We used frozen tumor tissues to extract DNA and performed next-generation sequencing for 51 targeted genes (including 29 HR-associated genes) in 701 ovarian cancers (298 high-grade serous cases, 189 clear cell cases, 135 endometrioid cases, 12 mucinous cases, 3 low-grade serous cases, and 64 others). HRD was defined as positive when at least one HR-associated gene was mutated. The frequencies of HRD and tumor BRCA1/2 mutations were 45.2% (317/701) and 18.5% (130/701), respectively, in the full analysis set. Next, we performed multivariate Cox proportional hazards regression analysis for progression-free survival (PFS) and overall survival (OS). Advanced-stage ovarian cancer patients with HRD had adjusted hazard ratios of 0.72 (95% CI, 0.55-0.94) and 0.57 (95% CI, 0.38-0.86) for PFS and OS, respectively, compared with those without HRD (p = 0.016 and 0.007). Our study demonstrated that mutations in HR-associated genes were associated with prognosis. Further studies are needed to investigate the prognostic impact of each HR-associated gene in ovarian cancer., (© 2023 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Importance: Randomized clinical trials examining the effectiveness of neoadjuvant chemotherapy (NACT) for advanced ovarian cancer predominantly included patients with high-grade serous carcinomas. The use and outcomes of NACT in less common epithelial carcinomas are understudied., Objective: To investigate the uptake and survival outcomes in treatment with NACT for less common histologic subtypes of epithelial ovarian cancer., Design, Setting, and Participants: A retrospective cohort study and systematic literature review with meta-analysis was conducted using the National Cancer Database from 2006 to 2017 and the National Cancer Institute's Surveillance, Epidemiology, and End Results Program from 2006 to 2019. Data analysis was performed from July 2022 to April 2023. The evaluation included patients with stage III to IV ovarian cancer with clear cell, mucinous, or low-grade serous histologic subtypes who received multimodal treatment with surgery and chemotherapy., Exposures: Exposure assignment per the sequence of treatment: primary debulking surgery (PDS) followed by chemotherapy (PDS group) or NACT followed by interval surgery (NACT group)., Main Outcomes and Measures: Temporal trends and characteristics of NACT use were assessed using multivariable analysis, and overall survival (OS) was assessed with the inverse probability of treatment weighting propensity score., Results: A total of 3880 patients were examined in the National Cancer Database including 1829 women (median age, 56 [IQR, 49-63] years) with clear cell, 1156 women (median age, 53 [IQR, 42-64] years) with low-grade serous, and 895 women (median age, 57 [IQR, 48-66] years) with mucinous carcinomas. NACT use increased in patients with clear cell (from 10.2% to 16.2%, 58.8% relative increase; P < .001 for trend) or low-grade serous (from 7.7% to 14.2%, 84.4% relative increase; P = .007 for trend) carcinoma during the study period. This association remained consistent in multivariable analysis. NACT use also increased, but nonsignificantly, in mucinous carcinomas (from 8.6% to 13.9%, 61.6% relative increase; P = .07 for trend). Across the 3 histologic subtypes, older age and stage IV disease were independently associated with NACT use. In a propensity score-weighted model, the NACT and PDS groups had comparable OS for clear cell (4-year rates, 31.4% vs 37.7%; hazard ratio [HR], 1.12; 95% CI, 0.95-1.33) and mucinous (27.0% vs 26.7%; HR, 0.90; 95% CI, 0.68-1.19) carcinomas. For patients with low-grade serous carcinoma, NACT was associated with decreased OS compared with PDS (4-year rates, 56.4% vs 81.0%; HR, 2.12; 95% CI, 1.55-2.90). Increasing NACT use and histologic subtype-specific survival association were also found in the Surveillance, Epidemiology, and End Results Program cohort (n = 1447). A meta-analysis of 4 studies, including the current study, observed similar OS associations for clear cell (HR, 1.13; 95% CI, 0.96-1.34; 2 studies), mucinous (HR, 0.93; 95% CI, 0.71-1.21; 2 studies), and low-grade serous (HR, 2.11; 95% CI, 1.63-2.74; 3 studies) carcinomas., Conclusions and Relevance: Despite the lack of data on outcomes of NACT among patients with less common carcinomas, this study noted that NACT use for advanced disease has gradually increased in the US. Primary chemotherapy for advanced-stage, low-grade serous ovarian cancer may be associated with worse survival compared with PDS.

The development of new treatments for gynecological malignancies has been conducted mainly through collaborative international phase III trials led by the United States and Europe. The survival outcomes of many gynecological malignancies have greatly improved as a result. Recent large-scale genome-wide association studies have revealed that drug efficacy and adverse event profiles are not always uniform. Thus, it is important to validate new treatment options in each country to safely and efficiently provide newly developed treatment options to patients with gynecological malignancies. The Japanese Gynecologic Oncology Group (JGOG) is conducting 5 cohort studies (JGOG 3026, 3027, 3028, 3030, and 3031) to establish real-world data (RWD) of poly(ADP-ribose) polymerase (PARP) inhibitor use in patients with advanced or recurrent epithelial ovarian cancer. The RWD constructed will be used to provide newly developed PARP inhibitors for women with advanced or recurrent ovarian cancer in a safer and more efficient manner as well as to develop further treatment options. In 2022, The JGOG, Korean Gynecologic Oncology Group, Chinese Gynecologic Cancer Society, and Taiwanese Gynecologic Oncology Group established the East Asian Gynecologic Oncology Trial Group to collaborate with East Asian countries in clinical research on gynecologic malignancies and disseminate new knowledge on gynecologic malignancies from Asia. The JGOG will conduct a collaborative integrated analysis of the RWD generated from Asian countries and disseminate real-world clinical knowledge regarding new treatment options that have been clinically implemented., Competing Interests: No potential conflict of interest relevant to this article was reported., (© 2023. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology, and Japan Society of Gynecologic Oncology.)

Background: This study aimed to evaluate the homologous recombination repair pathway deficiency (HRD) in ovarian high-grade serous carcinoma (HGSC)., Methods: In the ovarian cancer data from The Cancer Genome Atlas, we identified genes differentially expressed between tumours with and without HRD genomic scars and named these genes "HRDness signature". We performed SNP array, RNA sequencing, and methylation array analyses on 274 HGSC tumours for which targeted sequencing of 51 genes and clinical data were available to generate JGOG3025-TR2 dataset. The HRDness signature was tested on external datasets, including the JGOG3025-TR2 cohort, by computational scoring and machine-learning prediction., Results: High scores and positive predictions of the HRDness signature were significantly associated with BRCA alterations, genomic scar scores, and better survival. On the other hand, among cases with high scores and/or positive predictions, those with BRCA1 methylation showed poorer survival. In the JGOG3025-TR2 cohort, HRD status was significantly associated with the use of olaparib after relapse and progression-free survival after its initiation., Conclusions: The HRDness gene expression signature is associated with a good prognosis, while BRCA1 methylation is associated with a poor prognosis. The newly generated JGOG3025-TR2 dataset will be useful in future HGSC studies., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Objective: Sentinel lymph node (SLN) biopsy has been incorporated into surgical care for many malignancies; however, the utility has not been examined in ovarian cancer. This study examined population-level trends, characteristics, and outcomes related to SLN biopsy in early stage ovarian cancer., Methods: This is a retrospective cohort study querying the National Cancer Institute's Surveillance, Epidemiology, and End Result Program from 2003-2018. The study population consisted of 11,512 women with stage I ovarian cancer who had adnexectomy-based surgical staging including lymph node evaluation. Exposure allocation was based on SLN biopsy use. Main outcomes measured were (i) trends and characteristics associated with SLN biopsy use, assessed by multivariable logistic regression model, and (ii) overall survival assessed with inverse provability of treatment weighting propensity score., Results: SLN biopsy was performed in less than 1% of study population. In a multivariable analysis, recent surgery (2011-2018 versus 2003-2010, odds ratio [OR] 1.64, 95% confidence interval [CI] 1.03-2.59), smaller tumor size (< 10 versus ≥ 10 cm, OR 3.07, 95% CI 1.20-7.84), and East registry area (OR 2.74, 95% CI 1.73-4.36) remained independent characteristics for SLN biopsy use. In a propensity score weighted model, 5-year overall survival rate was 90.5% for the SLN biopsy-incorporated group and 88.6% for the lymphadenectomy group (hazard ratio 0.96, 95% CI 0.53-1.73)., Conclusion: SLN biopsy was rarely performed for early ovarian cancer surgery during the study period with insufficient evidence to interpret the survival effect. SLN biopsy in early ovarian cancer appears to be in early development phase, warranting further study and careful evaluation to assess feasibility and oncologic outcome., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Recent advances in human genome research have provided evidence for genotype-phenotype associations, pathogenicity, and clinical actionability of variants and genomic risk prediction of disease. However, the return of individual genomic results to healthy individuals is fraught with ethical and practical complexity., Methods: Individual genomic results were returned to BRCA1/2 pathogenic variant (PV) carriers of the Tohoku Medical Megabank cohort study participants with an information on hereditary breast and ovarian cancer syndrome (HBOC). One hundred and eighty participants, including 9 BRCA1/2 PV carriers, were asked about their willingness to receive individual genomic results, without revealing the gene name and related disorders, prior to the study. Of the 142 participants who responded, 103 showed willingness to know their genomic information. Each of the six BRCA1/2 PV carriers who consented to participate in the study received information about HBOC in person and underwent validation testing with blood resampling., Results: All participants were in their 60s or 70s; of the four females and two males, two had a history of breast cancer and five had a family history of HBOC-related cancers. All participants appreciated the information, without remarkable negative psychological impact of the return, and intended to undergo clinical risk surveillance. Five participants were accompanied by family members while receiving the results, and three first-degree female relatives wished to undergo genomic testing at the hospital., Conclusions: Our results suggest that returning actionable genomic information to participants in a population-based genome cohort study is beneficial for preventing or providing early-stage intervention for associated diseases., (© 2022. The Author(s), under exclusive licence to The Japanese Breast Cancer Society.)

The association between germline BRCA1 and BRCA2 pathogenic variants (mutations: gBRCAm) and ovarian cancer risk is well established. Germline testing alone cannot detect somatic BRCA1/2 pathogenic variants (sBRCAm), which is calculated based on the proportion of tumor BRCAm (tBRCAm) from tumor samples and gBRCAm. Homologous recombination deficiency (HRD) results mainly from genetic/epigenetic alterations in homologous recombination repair-related genes and can be evaluated by genomic instability status. In Japan, the prevalence of tBRCAm, sBRCAm, and HRD remains unclear. This multicenter, cross-sectional, observational study, CHaRacterIzing the croSs-secTional approach to invEstigate the prevaLence of tissue BRCA1/2 mutations in newLy diagnosEd advanced ovarian cancer patients (CHRISTELLE), evaluated the prevalence of tBRCAm, sBRCAm, and HRD in tumor specimens from newly diagnosed patients with ovarian cancer who underwent gBRCA testing. Of the 205 patients analyzed, 26.8% had a tBRCAm, including tBRCA1m (17.6%) and tBRCA2m (9.3%). The overall prevalence of tBRCAm, gBRCAm, sBRCAm, and HRD-positive status was 26.8%, 21.5%, 6.3%, and 60.0%, respectively. The calculated sBRCAm/tBRCAm ratio was 23.6% (13/55), and the prevalence of gBRCA variant of uncertain significance was 3.9%. These results suggest gBRCA testing alone cannot clearly identify the best course of treatment, highlighting the importance of sBRCA testing in Japan. The present results also suggest that testing for tBRCA and HRD should be encouraged in advanced ovarian cancer patients to drive precision medicine., (© 2022 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background: Outcomes with and without bevacizumab as first-line chemotherapy in Japanese-only ovarian cancer patients have not been reported. In this study, we report a retrospective study conducted at the Tohoku Gynecologic Cancer Unit., Patients and Methods: The study included 453 patients with stage III/IV ovarian, fallopian tube, and primary peritoneal cancer who received first-line platinum-based chemotherapy. The patients were divided into two groups: bevacizumab (168 patients) and without bevacizumab (285 patients). The primary endpoint was the rate of platinum-resistant recurrence and the secondary endpoints were the antitumor response, progression-free survival, overall survival, and adverse events., Results: The objective response rates for patients with measurable diseases treated with and without bevacizumab were 84.5% and 73.0%, respectively (P = 0.0066). Platinum-resistant recurrence in the groups treated with and without bevacizumab was noted in 31 (18.4%) and 111 (38.6%) patients, respectively (P < 0.0001). The median progression-free survival for the bevacizumab and without bevacizumab groups was 23 and 15 months, respectively (P = 0.0002), and the median overall survival was not reached and 49 months, respectively (P = 0.0005). Hypertension of grade 3 or higher was observed in 21 patients (12.5%) in the bevacizumab group (P < 0.001), and proteinuria was observed in 18 patients (10.7%) and 1 patient (0.3%) in the bevacizumab and without bevacizumab groups, respectively (P < 0.001). Intestinal perforation was observed in only one patient (0.6%) in the bevacizumab group., Conclusion: Combination and maintenance with bevacizumab in primary chemotherapy for advanced ovarian, fallopian tube, and primary peritoneal cancer was effective in reducing platinum-resistant recurrence rates and prolonging progression-free and overall survival., (© 2022. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)

Poly(ADP-ribose) polymerase (PARP) inhibitors theoretically promote synthetic lethality in cancer cells with homologous recombination deficiency (HRD). However, clinical evidence indicates that PARP inhibitors are also effective for treating HRD-negative ovarian cancer. The PARP inhibitor olaparib became available in Japan as a maintenance therapy for platinum-sensitive recurrent ovarian cancer regardless of homologous recombination status in April 2018. The purpose of this study was to identify potential clinical biomarkers for olaparib sensitivity in patients with recurrent ovarian cancer. Clinical information about the patients with recurrent ovarian cancer treated with olaparib maintenance therapy (OMT) was retrospectively collected. OMT duration was used as an indicator for olaparib sensitivity. The relationship between OMT duration and clinical parameters was statistically analyzed. We found a positive correlation between OMT duration and progression-free survival (PFS) or treatment free interval (TFI). In some cases, OMT duration exceeded PFS before olaparib introduction. We also found that more than half of the patients with measurable target lesions at the time of OMT introduction showed partial or complete response to OMT. These results validated the effectiveness of OMT and identified PFS and TFI as potential clinical markers for olaparib sensitivity in the patients with recurrent ovarian cancer.

Background: Poly (adenosine diphosphate)-ribose polymerase (PARP) inhibitors for tumors with homologous recombination deficiency (HRD), including pathogenic mutations in BRCA1/2 , have been developed. Genomic analysis revealed that about 20% of uterine leiomyosarcoma (uLMS) have HRD, including 7.5%-10% of BRCA1/2 alterations and 4%-6% of carcinomas of the uterine corpus, and 2.5%-4% of the uterine cervix have alterations of BRCA1/2 . Preclinical and clinical case reports suggest that PARP inhibitors may be effective against those targets. The Japanese Gynecologic Oncology Group (JGOG) is now planning to conduct a new investigator-initiated clinical trial, JGOG2052., Methods: JGOG2052 is a single-arm, open-label, multi-center, phase 2 clinical trial to evaluate the efficacy and safety of niraparib monotherapy for a recurrent or persistent rare fraction of gynecologic malignancies with BRCA1/2 mutations except for ovarian cancers. We will independently consider the effect of niraparib for uLMS or other gynecologic malignancies with BRCA1/2 mutations (cohort A, C) and HRD positive uLMS without BRCA1/2 mutations (cohort B). Participants must have 1-3 lines of previous chemotherapy and at least one measurable lesion according to RECIST (v.1.1). Niraparib will be orally administered once a day until lesion exacerbation or unacceptable adverse events occur. Efficacy will be evaluated by imaging through an additional computed tomography scan every 8 weeks. Safety will be measured weekly in cycle 1 and every 4 weeks after cycle 2 by blood tests and physical examinations. The sample size is 16-20 in each of cohort A and B, and 31 in cohort C. Primary endpoint is the objective response rate., Trial Registration: Japan Primary Registries Network (JPRN) Identifier: jRCT2031210264., Competing Interests: Takeda Pharmaceutical Company Limited did not have a role in the study design, and conflicts of interest regarding the conduct and outcome of clinical trials will be appropriately managed under the regulations of each implementing medical institution., (Copyright © 2022. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology, and Japan Society of Gynecologic Oncology.)

Epithelial ovarian cancer (EOC) is a fatal gynecologic cancer, and its poor prognosis is mainly due to delayed diagnosis. Therefore, biomarker identification and prognosis prediction are crucial in EOC. Altered cell metabolism is a characteristic feature of cancers, and metabolomics reflects an individual's current phenotype. In particular, plasma metabolome analyses can be useful for biomarker identification. In this study, we analyzed 624 metabolites, including uremic toxins (UTx) in plasma derived from 80 patients with EOC using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Compared with the healthy control, we detected 77 significantly increased metabolites and 114 significantly decreased metabolites in EOC patients. Especially, decreased concentrations of lysophosphatidylcholines and phosphatidylcholines and increased concentrations of triglycerides were observed, indicating a metabolic profile characteristic of EOC patients. After calculating the parameters of each metabolic index, we found that higher ratios of kynurenine to tryptophan correlates with worse prognosis in EOC patients. Kynurenine, one of the UTx, can affect the prognosis of EOC. Our results demonstrated that plasma metabolome analysis is useful not only for the diagnosis of EOC, but also for predicting prognosis with the variation of UTx and evaluating response to chemotherapy.

Platinum sensitivity is an important prognostic factor in patients with ovarian cancer. Chromodomain-helicase-DNA-binding protein 4 (CHD4) is a core member of the nucleosome remodeling and deacetylase complex, which functions as a chromatin remodeler. Emerging evidence indicates that CHD4 could be a potential therapeutic target for cancer therapy. The purpose of this study was to clarify the role of CHD4 in ovarian cancer and investigate its therapeutic potential focusing on platinum sensitivity. In an analysis of the Cancer Genome Atlas ovarian cancer dataset, CHD4 gene amplification was associated with worse overall survival. CHD4 mRNA expression was significantly higher in platinum-resistant samples in a subsequent clinical sample analysis, suggesting that CHD4 overexpression conferred platinum resistance to ovarian cancer cells, resulting in poor patient survival. In concordance with these findings, CHD4 knockdown enhanced the induction of apoptosis mediated by cisplatin in ovarian cancer cells TOV21G and increased cisplatin sensitivity in multiple ovarian cancer cells derived from different subtypes. However, CHD4 knockdown did not affect the expression of RAD51 or p21, the known targets of CHD4 in other cancer types that can modulate platinum sensitivity. Knockdown and overexpression assays revealed that CHD4 positively regulated the expression of multi-drug transporter MDR1 and its coding protein p-glycoprotein. In addition, a first-in-class CHD4/SMARCA5 inhibitor ED2-AD101 showed synergistic interactions with cisplatin. Our findings suggest that CHD4 mediates platinum sensitivity by modulating MDR1 expression in ovarian cancer. Further, CHD4 suppression has a potential to be a novel therapeutic strategy in combination with platinum agents., Competing Interests: The authors have declared that no competing interests exist.

Background: We evaluated the efficacy of intraperitoneal (IP) carboplatin in combination with dose-dense paclitaxel (ddTCip) for suboptimal residual ovarian cancer., Methods: This was a phase 2 study to evaluate ddTCip. Patients with stage II-IV ovarian carcinoma, who underwent primary cytoreductive surgery and had radiologically evaluable disease after surgery, were eligible to participate in this study. IP carboplatin (AUC = 6) was administered on day 1, and intravenous paclitaxel (80 mg/m 2 ) was administered on days 1, 8 and 15. The primary endpoint was response rate. Secondary endpoints included progression-free survival (PFS), overall survival (OS) and safety. Interval- debulking surgery followed by the same regimen was allowed when indicated., Results: A total of 117 patients were considered eligible for this study prior to surgery and temporarily registered. Of the 117 patients, 76 patients met the inclusion criteria and were enrolled in this study. Fifty-nine (83.1%) patients had objective clinical responses. Median PFS and OS were 18.3 and 55.5 months, respectively. Sixty-four (84.2%) patients had grade 3/4 neutropenia, 43 (56.5%) patients had anaemia and 17 (22.4%) patients had thrombocytopenia. Port-related adverse events occurred in nine (11.8%) patients., Conclusions: Front-line chemotherapy with ddTCip therapy appears safe and effective, even for patients with suboptimal residual ovarian cancer., Trial Registration: UMIN Clinical Trials Registry (ID: UMIN000001713) on February 16th, 2009.

Purpose: To compare the efficacy, safety, and tolerability profiles of pegylated liposomal doxorubicin and carboplatin (PLDC) with those of gemcitabine and carboplatin (GC) for the treatment of patients with platinum-sensitive recurrent ovarian cancer., Methods: Ovarian cancer patients with recurrence > 6 months after first-line platinum and taxane-based therapies were randomly assigned to PLDC [pegylated liposomal doxorubicin 30 mg/m 2 plus carboplatin area under the curve (AUC) 5 mg/mL/min on day 1] every 4 weeks or GC (gemcitabine 1000 mg/m 2 on days 1 and 8 plus carboplatin AUC 4 mg/mL/min on day 1) every 3 weeks for at least 6 cycles. The primary endpoint was progression-free survival, and overall response rate, overall survival, toxicity, and dose administration were secondary endpoints., Results: One-hundred patients (49 PLDC; 51 GC) were randomly assigned. Over a median follow-up of 24 months, the median progression-free survival was 12.0 months (95% CI 9.2-15.0) for PLDC and 9.8 months (8.9-12.3) for GC [HR 0.69 (0.455-1.047)] with a difference of 2.2 months. The response rate was 57.1% (41.0-72.3) for PLDC and 56.4% (39.6-72.2) for GC. No obvious differences in toxicity (G3/4) were noted between arms. The median relative dose intensity of planned dose per week was 88.9% for pegylated liposomal doxorubicin and 53.1% for gemcitabine (p < 0.0001)., Conclusions: PLDC and GC are both good treatment candidates for platinum-sensitive recurrent ovarian cancer patients; however, the dose intensity was lower for GC than for PLDC. PLDC had a more favorable risk-benefit profile than that of GC for patients.

Objective: To examine the association between postoperative chemotherapy and survival of women with stage IC mucinous ovarian cancer (MOC)., Methods: Comprehensive nationwide tumor registry data from the Commission on Cancer-accredited facilities in the United States from 2004 to 2014 were retrospectively examined. Women with stage IC MOC who underwent primary surgery followed by postoperative chemotherapy were compared to those who did not receive. Clinico-pathological factors associated with chemotherapy use, and overall survival associated with chemotherapy use were examined with multivariable models and propensity score inverse probability of treatment weighting (IPTW). External validation was performed by examining the Surveillance, Epidemiology, and End Results Program from 1988 to 2014., Results: There were 532 (58.5%) women who received postoperative chemotherapy and 377 (41.5%) women who did not. On multivariable analysis, those with moderately-/poorly-differentiated tumors, large tumor size, and who underwent lymphadenectomy were more likely to receive postoperative chemotherapy whereas young women and those with capsule rupture alone were less likely to receive postoperative chemotherapy (all, P < 0.05). After IPTW, there was no difference in overall survival among women who received postoperative chemotherapy versus those who did not on multivariable analysis (adjusted 4-year rates: 85.8% versus 86.3%, adjusted-hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.60-1.31). Similarly, there was no benefit with chemotherapy regardless of patient age, tumor differentiation, performance of nodal dissection, and substage groups. Among 912 cases in the validation cohort (postoperative chemotherapy use, n = 520 [57.0%]), postoperative chemotherapy use was not associated with cause-specific survival (adjusted-HR 1.296, 95% CI 0.846-1.984, P = 0.233) or overall survival (adjusted-HR 1.131, 95% CI 0.849-1.508, P = 0.400)., Conclusion: Postoperative chemotherapy was received by fewer than 60% of women with stage IC MOC, and postoperative chemotherapy was not associated with improved survival., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The PHLDA family (pleckstrin homology-like domain family) of genes consists of 3 members: PHLDA1, 2, and 3. Both PHLDA3 and PHLDA2 are phosphatidylinositol (PIP) binding proteins and function as repressors of Akt. They have tumor suppressive functions, mainly through Akt inhibition. Several reports suggest that PHLDA1 also has a tumor suppressive function; however, the precise molecular functions of PHLDA1 remain to be elucidated. Through a comprehensive screen for p53 target genes, we identified PHLDA1 as a novel p53 target, and we show that PHLDA1 has the ability to repress Akt in a manner similar to that of PHLDA3 and PHLDA2. PHLDA1 has a so-called split PH domain in which the PH domain is divided into an N-terminal (β sheets 1-3) and a C-terminal (β sheets 4-7 and an α-helix) portions. We show that the PH domain of PHLDA1 is responsible for its localization to the plasma membrane and binding to phosphatidylinositol. We also show that the function of the PH domain is essential for Akt repression. In addition, PHLDA1 expression analysis suggests that PHLDA1 has a tumor suppressive function in breast and ovarian cancers., (© 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

This study seeks to identify risk factors associated with ovarian metastasis and to characterize a population with minimum risk of ovarian metastasis in young women with stage IB-IIB cervical cancer. This was a nation-wide multicenter retrospective study in Japan examining consecutive cases of surgically-treated women with clinical stage IB-IIB cervical cancer who had oophorectomy at radical hysterectomy (n = 5,697). Multivariable analysis was performed to identify independent risk factors for ovarian metastasis. Ovarian metastasis was seen in 70 (1.2%, 95% confidence interval 0.9-1.5) cases. In the entire cohort, adenocarcinoma, lympho-vascular space invasion, uterine corpus tumor invasion, and pelvic/para-aortic nodal metastases remained independent risk factors for ovarian metastasis (all, adjusted-p < 0.05). In a sensitivity analysis of 3,165 women aged <50 years (ovarian metastasis, 1.0%), adenocarcinoma, parametrial tumor involvement, uterine corpus tumor involvement, and pelvic/para-aortic nodal metastases remained independent risk factors for ovarian metastasis (all, adjusted-P < 0.05). In the absence of these five risk factors (representing 46.1% of women aged <50 years), the incidence of ovarian metastasis was 0.14%. With the presence of adenocarcinoma alone (representing 18.9% of women aged <50 years), the incidence of ovarian metastasis was 0.17% and was not associated with increased risk of ovarian metastasis compared to the subgroup without any risk factors (p = 0.87). In conclusion, nearly two thirds of women aged <50 years with clinical stage IB-IIB cervical cancer had no risk factor for ovarian metastasis or had adenocarcinoma alone: these subgroups had ovarian metastasis rates of around 0.1% and may be a candidate population for ovarian conservation at surgical treatment., (© 2017 UICC.)

Background: Health-related quality of life (HRQoL) was a secondary end point in AGO-OVAR 16, which randomized 940 patients with EOC after first-line chemotherapy to maintenance pazopanib (PZ) or placebo (P). Additional post hoc analyses were carried out to investigate additional patient-centered end points., Patients and Methods: HRQoL was measured with EORTC-QLQ-C30, QLQ-OV28 and EQ-5D-3L. Pre-specified end points included mean differences in HRQoL between treatment arms. Exploratory analyses included quality-adjusted progression-free survival (QAPFS), impact of specific symptoms and progressive disease (PD) on HRQoL and time to second-line chemotherapy. The objective was to provide clinical perspective to the significant median PFS gain of 5.6 months with PZ., Results: There were statistically significant differences between PZ and P in QLQ-C30 global health status [5.5 points; 95% confidence interval (CI), 0.7-10.4, P = 0.024] from baseline to 25 months, but not EQ-5D-3L (0.018 points; 95% CI - 0.033 to 0.069, P = 0.485). The impact of diarrhea was captured in QLQ-OV28 Abdominal/GI-Symptoms scale (8.1 points; 95% CI 3.6-12.5, P = 0.001). QAPFS was 386 days (95% CI 366-404 days) with PZ versus 359 days (95% CI 338-379 days) with placebo (P = 0.052). PD was associated with a decline in HRQoL (P < 0.0001). Median time to second-line chemotherapy was 19.7 months with PZ and 15.0 months with P [hazard ratio (HR) 0.72, 95% CI 0.69-0.86, P = 0.0001]., Conclusions: There were small to no significant mean score differences in global HRQoL and EQ5D-3L between PZ and placebo, respectively, despite the increased toxicity of PZ. Exploratory end points including QAPFS, impact of specific symptoms on HRQoL during treatment and at PD help place the PFS gain with PZ in context and interpret the results. Additional patient-centered end points should be considered in trials of maintenance therapy in EOC beyond mean differences in HRQoL scores alone, to support the benefit to patients of prolongation of PFS., Clinical Trials Registration Number: NCT00866697.

Background: Bevacizumab, which targets vascular endothelial growth factor (VEGF)-A, has recently been proven to be effective for the treatment of epithelial ovarian cancer (EOC). Thus, interest in VEGF-A has increased. There are few reports on concomitant detection of both ligands and its soluble receptors in serum samples, and the significance of serum VEGF-A in EOC is unclear, unlike the situation with tissue samples. We conducted the present study to explore the levels of serum VEGF family and its receptors and to evaluate their utility as prognostic biomarkers., Methods: A total of 128 patients with EOC, who were consecutively treated at Tottori University Hospital between 2006 and 2012, were included. Blood samples were collected before initial surgery. Serum concentrations of VEGF-A, VEGF-C, VEGFR-1, and VEGFR-2 were analyzed by enzyme-linked immunosorbent assay. We also examined the mRNA and protein expression of VEGF-A in tumor tissue from 30 cases by real-time reverse transcription polymerase chain reaction and immunohistochemistry., Results: The levels of VEGF-A in patients with stage III/IV disease were significantly higher than those with stage I/II disease (P = 0.0036). On the other hand, the level of VEGFR-2 in stage III/IV was significantly lower than that in stage I/II (P = 0.0026). With the cutoff value of VEGF/VEGFRs at the median level, the overall survival (OS) for patients with high VEGF-A levels was significantly lower than those with low levels (P = 0.015). Patients with high VEGFR-2 levels showed better prognosis than those with low VEGFR-2 levels (P = 0.023). Multivariate analysis revealed that International Federation of Gynecology and Obstetrics stage and serum VEGF-A were independent prognostic factors for OS [hazard ratio 2.01, 95% confidence interval (1.13-3.63), P = 0.017]. There was no significant correlation between mRNA or protein expression and serum levels of VEGF-A., Conclusions: Serum VEGF-A is an independent prognostic factor for OS in patients with EOC, implying that serum VEGF-A is a prognostic biomarker for EOC. Further study to validate the data is needed.

There has been significant progress in the understanding of the pathology and molecular biology of rare ovarian cancers, which has helped both diagnosis and treatment. This paper provides an update on recent advances in the knowledge and treatment of rare ovarian cancers and identifies gaps that need to be addressed by further clinical research. The topics covered include: low-grade serous, mucinous, and clear cell carcinomas of the ovary. Given the molecular heterogeneity and the histopathological rarity of these ovarian cancers, the importance of designing adequately powered trials or finding statistically innovative ways to approach the treatment of these rare tumors has been emphasized. This paper is based on the Rare Ovarian Tumors Conference for Young Investigators which was presented in Tokyo 2015 prior to the 5th Ovarian Cancer Consensus Conference of the Gynecologic Cancer InterGroup (GCIG)., Competing Interests: No potential conflict of interest relevant to this article was reported., (Copyright © 2017. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology.)

A new cell line of human ovarian clear cell carcinoma (CCC), TU-OC-2, was established and characterized. The cells were polygonal in shape, grew in monolayers without contact inhibition and were arranged in islands like pieces of a jigsaw puzzle. The chromosome numbers ranged from 41 to 96. A low rate of proliferation was observed and the doubling time was 37.5 h. The IC50 values of cisplatin, 7-ethyl-10-hydroxycamptothecin (SN38), which is an active metabolite of camptothecin, and paclitaxel were 7.7 μM, 17.7 nM and 301 nM, respectively. The drug sensitivity assay indicated that TU-OC-2 was sensitive to SN38, but resistant to cisplatin and paclitaxel. Mutational analysis revealed that TU-OC-2 cells have no mutations of PIK3CA in exons 9 and 20 and of TP53 in exons 4-9. We observed the loss of ARID1A protein expression in TU-OC-2 cells by western blot analysis and in the original tumor tissue by immunohistochemistry. This cell line may be useful for studying the chemoresistant mechanisms of CCC and exploring novel therapeutic targets such as the ARID1A-related signaling pathway.

Objective: AGO-OVAR 16 demonstrated that pazopanib maintenance therapy significantly increased progression-free survival (PFS) in patients with ovarian cancer whose disease had not progressed after first-line therapy. In a sub-study, we evaluated the effect of clinically important germline BRCA1 and BRCA2 mutations on PFS., Methods: Of 940 AGO-OVAR 16 participants, 664 had BRCA1/2 exon sequencing data (pazopanib, n=335; placebo, n=329). A Cox model was used to test the association between genetic variants and PFS., Results: Ninety-seven of 664 patients (15%) carried clinically important BRCA1/2 mutations (BRCA1/2 carriers: pazopanib 14%, placebo 16%). Median PFS was longer in BRCA1/2 mutation carriers than in BRCA1/2 non-carriers in the placebo arm (30.3 vs 14.1 months, hazard ratio, 0.48; 95% confidence interval [CI]: 0.29-0.78; P=0.0031); a similar non-significant trend was noted with pazopanib (30.2 vs 17.7 months, hazard ratio, 0.64; 95% CI: 0.40-1.03; P=0.069). Among BRCA1/2 non-carriers, PFS was longer for pazopanib-treated patients than placebo-treated patients (17.7 vs 14.1 months, hazard ratio, 0.77; 95% CI: 0.62-0.97; P=0.024). Among BRCA1/2 carriers, there was no significant PFS difference between treatments, although numbers were small (pazopanib, 46; placebo, 51), resulting in a wide CI (hazard ratio, 1.36; 95% CI: 0.66-2.82)., Conclusions: Patients with clinically important BRCA1/2 mutations had better prognosis. BRCA1/2 mutation status might be added as strata in future trials in primary ovarian cancer., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: Pazopanib is an oral, multikinase inhibitor of vascular endothelial growth factor receptor (VEGFR) -1/-2/-3, platelet-derived growth factor receptor (PDGFR) -α/-β, and c-Kit. Preclinical and clinical studies support VEGFR and PDGFR as targets for advanced ovarian cancer treatment. This study evaluated the role of pazopanib maintenance therapy in patients with ovarian cancer whose disease did not progress during first-line chemotherapy., Patients and Methods: Nine hundred forty patients with histologically confirmed cancer of the ovary, fallopian tube, or peritoneum, International Federation Gynecology Obstetrics (FIGO) stages II-IV, no evidence of progression after primary therapy consisting of surgery and at least five cycles of platinum-taxane chemotherapy were randomized 1:1 to receive pazopanib 800 mg once per day or placebo for up to 24 months. The primary end point was progression-free survival by RECIST 1.0 assessed by the investigators., Results: Maintenance pazopanib prolonged progression-free survival compared with placebo (hazard ratio [HR], 0.77; 95% CI, 0.64 to 0.91; P = .0021; median, 17.9 v 12.3 months, respectively). Interim survival analysis based on events in 35.6% of the population did not show any significant difference. Grade 3 or 4 adverse events of hypertension (30.8%), neutropenia (9.9%), liver-related toxicity (9.4%), diarrhea (8.2%), fatigue (2.7%), thrombocytopenia (2.5%), and palmar-plantar erythrodysesthesia (1.9%) were significantly higher in the pazopanib arm. Treatment discontinuation related to adverse events was higher among patients treated with pazopanib (33.3%) compared with placebo (5.6%)., Conclusion: Pazopanib maintenance therapy provided a median improvement of 5.6 months (HR, 0.77) in progression-free survival in patients with advanced ovarian cancer who have not progressed after first-line chemotherapy. Overall survival data to this point did not suggest any benefit. Additional analysis should help to identify subgroups of patients in whom improved efficacy may balance toxicity (NCT00866697)., (© 2014 by American Society of Clinical Oncology.)

Patients with clear cell carcinoma of the ovary (OCCC) have poor survival due to resistance to standard chemotherapy. OCCC has frequent activating mutations of the PIK3CA gene. The present study was conducted to clarify the efficacy of the inhibition of the PI3K-AKT-mTOR pathway in OCCC. We used 8 OCCC cell lines and 5 ovarian serous adenocarcinoma (OSAC) cell lines. The mutation status of the PIK3CA and KRAS genes was examined by direct sequencing. The IC50 values of NVP-BEZ235 (BEZ235) and temsirolimus were determined by WST-8 assay. Protein expression levels of PI3K-AKT-mTOR pathway molecules were examined by western blotting. Cell cycle distribution was analyzed by flow cytometry. Annexin V staining was used for detecting apoptosis. We also investigated the effects of BEZ235 on OCCC tumor growth in a nude mouse xenograft model. Four of the 8 OCCC cell lines showed a PIK3CA mutation while none of the 5 OSAC cell lines showed a mutation. The IC50 values of BEZ235 for the OCCC cell lines were lower than these values for the OSAC cell lines. The IC50 value of temsirolimus was higher than BEZ235 in the OCCC cell lines. The PIK3CA mutation was more frequently noted in OCCC than OSAC cells, but the sensitivity of these cell lines to BEZ235 or temsirolimus was not related to the mutation status. pHER3 and pAkt proteins were expressed more frequently in OCCC compared with OSAC. However, protein expression levels were distributed widely, and were not related to the sensitivity. Treatment with BEZ235 suppressed expression of pAkt, although treatment with temsirolimus did not. OCCC cells exhibited G1 phase arrest after treatment with BEZ235 and apoptosis with a higher concentration of the agent. BEZ235 significantly inhibited tumor growth in mice bearing OVISE and TU-OC-1 cell tumors. The present study indicated that the PI3K-AKT-mTOR pathway is a potential target for OCCC, and that BEZ235 warrants investigation as a therapeutic agent.

Ovarian mucinous adenocarcinoma (MAC) resists standard chemotherapy and is associated with poor prognosis. A more effective treatment is needed urgently. The present study assessed the possibility of molecular-targeted therapy with a novel dual inhibitor of phosphatidylinositol 3'-kinase (PI3K) and mammalian target of rapamycin (mTOR), NVP-BEZ235 (BEZ235) to treat of MAC. Seven human MAC cell lines were used in this study. The sensitivity of the cells to BEZ235, temsirolimus, and anticancer agents was determined with the WST-8 assay. Cell cycle distribution was assessed by flow cytometry, and the expression of proteins in apoptotic pathways and molecules of the PI3K/Akt/mTOR signaling pathways was determined by Western blot analysis. We also examined the effects of BEZ235 on tumor growth in nude mice xenograft models. The cell lines showed half-maximal inhibitory concentration values of BEZ235 from 13 to 328 nmol/L. Low half-maximal inhibitory concentration values to BEZ235 were observed in MCAS and OMC-1 cells; these 2 lines have an activating mutation in the PIK3CA gene. NVP-BEZ235 down-regulated the protein expression of phosphorylated (p-) Akt, p-p70S6K, and p-4E-BP1, suppressed cell cycle progression, up-regulated the expression of cleaved PARP and cleaved caspase 9, and increased apoptotic cells. Synergistic effects were observed on more than 5 cell lines when BEZ235 was combined with paclitaxel or cisplatin. The treatment of mice bearing OMC-1 or RMUG-S with BEZ235 significantly suppressed tumor growth in MAC xenograft models without severe weight loss. We conclude that the PI3K/Akt/mTOR pathway is a potential therapeutic target and that BEZ235 should be explored as a therapeutic agent for MAC.

Objective: Checkpoint kinase (Chk) inhibitors are thought to increase the cytotoxic effects of DNA-damaging agents and are undergoing clinical trials. The present study was aimed to assess the potential to use the Chk1 and Chk2 inhibitor, AZD7762, with other anticancer agents in chemotherapy to treat ovarian clear cell carcinoma., Methods: Four ovarian clear cell carcinoma cell lines were used in this study. We treated the cells with AZD7762 and anticancer agents, then assessed cell viability, cell cycle distribution, apoptosis, and the expression of protein in apoptotic pathways and molecules downstream of the Chk signaling pathways. We also investigated the effects of these drug combinations on tumor growth in a nude mouse xenograft model., Results: Synergistic effects from the combination of AZD7762 and cisplatin were observed in all 4 cell lines. However, we observed additive effects when AZD7762 was combined with paclitaxel on all cell lines tested. AZD7762 effectively suppressed the Chk signaling pathways activated by cisplatin, dramatically enhanced expression of phosphorylated H2A.X, cleaved caspase 9 and PARP, decreased the proportion of cells in the gap 0/ gap 1 phase and the synthesis-phase fraction, and increased apoptotic cells. Combinations of small interfering RNA against Chk 1 and small interfering RNA against Chk2 enhanced the cytotoxic effect of cisplatin in both RMG-I and KK cells. Finally, treating mice-bearing RMG-I with AZD7762 and cisplatin significantly suppressed growth of tumors in a xenograft model., Conclusions: The present study indicates that chemotherapy with AZD7762 and cisplatin should be explored as a treatment modality for women with ovarian clear cell carcinoma.

A new cell line of human ovarian clear cell adenocarcinoma (CCC), TU-OC-1, was established and characterized. The cells showed a polygonal-shaped morphology and grew in monolayers without contact inhibition and were arranged like a jigsaw puzzle. The chromosome numbers ranged from 64 to 90. A low rate of proliferation was observed, similar to other CCC cell lines tested (OVTOKO, RMG-I, and OVAS), and the doubling time was 38.4 h. The respective IC50 values of cisplatin and paclitaxel were 12.2 μM and 58.3 nM. Mutational analysis revealed that TU-OC-1 cells harbored a PIK3CA mutation at codon 542 (E542K) in exon 9, which is a mutation hot spot on this gene. We observed that phosphorylated Akt protein was overexpressed in TU-OC-1 cells by western blot analysis. Heterotransplantation to nude mice produced tumors that reflected the original. This cell line may be useful to study the chemoresistant mechanisms of CCC and contribute to novel treatment strategies.

A new line of human ovarian serous adenocarcinoma cells, TU-OS-4, was established and characterized. The cells showed a short, spindle-shaped morphology and grew in monolayers without contact inhibition while forming an arrangement resembling a jigsaw puzzle. Chromosome numbers ranged from 55 to 73. The proliferation rate was lower than other serous adenocarcinoma cell lines tested (KF, SHIN-3, and SK-OV-3), and the doubling time was 53.3 h. Western blot analysis showed that TU-OS-4 cells overexpressed epidermal growth factor receptor, human epidermal growth factor receptor (HER) 2, and phosphorylated HER2 protein. The IC(50) values to cisplatin, paclitaxel, and lapatinib were 25.8 μM, 686 nM, and 183 nM, respectively. Heterotransplantation in nude mice reflected the original tumor of the cells. These results suggested that this cell line would be useful to study chemoresistant mechanisms and contribute to establishing novel treatment strategies for patients with ovarian cancer.

Objective: This study was aimed to elucidate the roles of the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3'-kinase (PI3K)/Akt pathways in regulating cytotoxicity induced by cisplatin (CDDP) in ovarian carcinoma cells., Methods: We treated 7 ovarian cancer cell lines with CDDP alone or with CDDP and either a PI3K inhibitor (LY294002), a MEK inhibitor (PD98059), or a MEK/ERK activator (phorbol 12-myristate 13-acetate [PMA]) and assessed cell viability, expression of MEK/ERK and PI3K/Akt, cell cycle distribution, and apoptosis. We also investigated the effect of combination treatment on survival in a xenograft model., Results: The cell lines showed half-maximal inhibitory concentrations (IC50) of CDDP from 2.4 to 26.9 μmol/L. KFr, a CDDP-resistant cell line developed from KF cells, showed an IC50 of CDDP of 9.6 μmol/L. Five of the cell lines with IC50 values of 9.6 μmol/L or greater were defined as CDDP-resistant. Cisplatin and LY294002 had an additive effect on inhibiting cell growth, and CDDP and PD98059 had and antagonistic effect on cell growth in all cell lines. In CDDP-resistant cells, CDDP and PMA dramatically suppressed the cell growth, up-regulated the expression of phosphorylated ERK and cleaved caspase-9, down-regulated the expression of checkpoint kinases, and increased the proportion of cells in the synthesis-phase fraction and apoptotic cells. The treatment of nude mice with CDDP and PMA prolonged survival in an ovarian cancer xenograft model., Conclusions: The present study indicates that further study is warranted to determine the effectiveness of combination treatment with CDDP and PMA for platinum-resistant ovarian carcinoma.

Purpose: Nedaplatin (NDP), a platinum derivative, has been developed to reduce nephrotoxicity and gastrointestinal toxicity of cisplatin. The pharmacokinetic profile of NDP is similar to that of carboplatin (CBDCA). The optimal dosing for CBDCA is determined by the area under the curve (AUC) using Calvert's formula. However, the administration dose of nedaplatin (NDP) is determined based on the body surface area in clinical treatment. Ishibashi et al. reported a formula for predicting NDP clearance based on renal function like Calvert's formula for CBDCA. We conducted the present study to evaluate the Ishibashi's formula., Methods: A total of 22 patients with cervical or ovarian cancer, who underwent chemotherapy consisting of NDP and irinotecan (CPT-11), were examined in this study. Blood samples were collected at 0, 1, 2, 4, and 6 h after the end of infusion of NDP (48-80 mg/m(2)), and free platinum concentrations were measured. Observed AUCs were compared with predicted AUCs, which were calculated by the Ishibashi's formula. In addition, the relative reduction in platelets (PLTs) was assessed as a parameter of adverse effects., Results: The observed AUC of NDP ranged from 4 to 14 (μg h(-1) ml(-1)) with large variation. The predicted AUC based on renal function was correlated with the observed AUC. There was a relationship between observed AUC and the decrease in PLTs., Conclusions: Ishibashi's formula would be predictable and useful for estimating the individual dose of NDP.

Aim: To evaluate the feasibility of biweekly paclitaxel treatment as maintenance chemotherapy for patients with advanced müllerian carcinoma., Methods: Thirty patients with stage III or IV ovarian, fallopian tube, and peritoneal cancers who underwent primary optimal surgery and standard 6 cycles of carboplatin/taxane-based chemotherapy and exhibited a complete clinical response were entered in this study. Paclitaxel 80 mg/m(2) was administered biweekly for 12 cycles. Patients were evaluated monthly for treatment-related toxicity., Results: Four patients, including 3 disease progressions and 1 bone marrow suppression, came off the protocol therapy. Twenty-six (86.7%) patients received complete treatment. Although the major toxicity was neutropenia, most of those patients (27/30, 90.0%) did not experience grade 3 or 4 neutropenia. Twenty-four (80.0%) patients showed persistent grade 1 neuropathy and the remaining 6 (20.0%) did not as a result of prior therapy. However, none experienced neuropathy progression during or after the protocol therapy. Most (17/22, 77.3%) of the completely treated patients experienced a regression of symptoms during and after therapy., Conclusion: Biweekly paclitaxel therapy is well tolerated by patients with advanced müllerian carcinoma and is therefore acceptable as a candidate for maintenance chemotherapy in these patients., (Copyright © 2012 S. Karger AG, Basel.)

Purpose: The mTOR pathway is thought to be a central regulator of proliferation and survival of cells. Rapamycin and its analogs are undergoing clinical trials in patients with epithelial ovarian cancer. This study aimed to assess the potential to use rapamycin and anticancer agents in combination for first- and second-line chemotherapy to treat ovarian cancer., Experimental Design: We used six ovarian serous adenocarcinoma cell lines (KF, KOC-2S, SHIN-3, SK-OV-3, TU-OS-3, and TU-OS-4) in this study. We treated the cells with rapamycin and anticancer agents, then assessed cell viability, apoptosis, and the expression of protein in apoptotic pathways and molecules downstream of the mTOR signaling pathways. We also investigated the effect of these drug combinations on survival in nude mouse xenograft models., Results: Synergistic effects were observed in five cell lines from the combination of etoposide and rapamycin. However, we observed antagonistic effects when rapamycin was combined with gemcitabine, cisplatin, or paclitaxel on more than two cell lines. Rapamycin dramatically enhanced apoptosis induced by etoposide and the expression of cleaved caspase 9. This effect was associated with upregulation of phosphorylated c-Jun and downregulation of Bcl-xL. The synergistic interaction of rapamycin and etoposide was lower when the c-Jun pathway was suppressed by a c-Jun N-terminal kinase inhibitor (SP600125). Finally, treating nude mice with rapamycin and etoposide significantly prolonged survival in the model mice with ovarian cancer xenografts., Conclusions: Chemotherapy with rapamycin and etoposide combined is worth exploring as a treatment modality for women with epithelial ovarian cancer.

Objective: We conducted the present study to clarify the clinicopathological characteristics of mucinous adenocarcinoma., Methods: Two hundred twenty-five patients were diagnosed with mucinous adenocarcinoma at individual institutes and underwent primary treatment between 1998 and 2003. Of these patients, 189 patients who could undergo central pathological review were enrolled in this study. Of 189 patients undergoing central pathological review, 64 patients (33.9%) were diagnosed with mucinous invasive adenocarcinoma, 45 mucinous intraepithelial carcinoma, and 42 mucinous tumor of borderline malignancy. Twenty-five patients were diagnosed with other histological subtypes, including 8 endometrioid adenocarcinoma, 5 clear cell carcinoma, 3 serous adenocarcinoma, and 4 mixed type. There were 13 cases of metastatic mucinous adenocarcinoma, including 7 pseudomyxoma peritonei. Four hundred thirty-three patients with serous adenocarcinoma were used as controls., Results: Forty-five patients with mucinous invasive carcinoma were in FIGO I-II stages and 19 in III-IV stages. There was no difference in the outcome between mucinous invasive adenocarcinoma and serous adenocarcinoma in I-II stage patients and III-IV stage patients with optimal operation. In contrast, patients with mucinous invasive adenocarcinoma receiving suboptimal operation showed a significantly worse prognosis (survival rate: 27.8% vs. 61.5%). The response rate to chemotherapy for mucinous invasive adenocarcinoma was significantly lower than for serous adenocarcinoma (12.5% vs. 67.7%)., Conclusions: The diagnosis of mucinous invasive adenocarcinoma was difficult. Since patients with mucinous invasive adenocarcinoma had a lower response to chemotherapy, aggressive cytoreductive surgery was an effective treatment to improve the prognosis for advanced stage patients. A new chemotherapeutic regimen should be established for mucinous adenocarcinoma of the ovary.

Resistance of ovarian mucinous adenocarcinoma to standard chemotherapy with paclitaxel and carboplatin is associated with poor prognosis, and an effective treatment is needed. The present study aimed to identify an effective chemotherapy for ovarian mucinous adenocarcinoma. Five human ovarian mucinous adenocarcinoma cell lines (MN-1, OMC-1, RMUG-L, RMUG-S, TU-OM-1) were used in this study. Sensitivity of the cells to the anticancer agents was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and we assessed drug sensitivity by calculating the assay area under the curve for each agent. Protein expression was confirmed by Western blot analysis. We also examined the efficacy of combination chemotherapy on survival in a xenograft model of nude mice. The IC(50) to anticancer agents ranged widely. The assay area under the curve indicated that two of five cell lines (MN-1, TU-OM-1) were sensitive to oxaliplatin, 5-fluorouracil and etoposide, and only one (TU-OM-1) was sensitive to 7-ethyl-10-hydroxycamptothecin, which is an active metabolite of camptothecin. All cell lines were resistant to cisplatin and paclitaxel. The combination of oxaliplatin and 5-fluorouracil resulted in additive or synergistic effects on all cell lines. The combination of oxaliplatin and 5-fluorouracil significantly prolonged survival in a ovarian mucinous adenocarcinoma xenograft model of nude mice. Protein expression levels of the excision repair cross-complementation group 1 were lower in oxaliplatin sensitive cell lines. Exposure to 5-fluorouracil down-regulated cross-complementation group 1 expression in ovarian mucinous adenocarcinoma cells. We conclude that combination chemotherapy consisting of oxaliplatin and 5-fluorouracil was an effective treatment for ovarian mucinous adenocarcinoma and may be a pivotal candidate for a novel treatment strategy.

Clear cell carcinoma (CCC) of the ovary has been recognized to show resistance to anticancer agents in the first-line chemotherapy. Our aim was to evaluate the effect of second-line chemotherapy in a retrospective study. A total of 75 patients diagnosed with CCC and treated between 1992 and 2002 in collaborating hospitals were reviewed. Criteria for the patients' enrollment were 1) diagnosis of pure-type CCC at the initial operation, 2) treatment after one systemic postoperative chemotherapy, 3) measurable recurrent or refractory tumor, 4) at least two cycles of second-line chemotherapy and assessable for the response, and 5) adequate clinical information. Regimens of first-line chemotherapy were conventional platinum-based therapy in 33 cases, paclitaxel plus platinum in 24 cases, irinotecan plus platinum in 9 cases, and irinotecan plus mitomycin C in 7 cases. Treatment-free periods were more than 6 months in 24 cases (group A) and less than 6 months in 51 cases (group B). In group A, response was observed in two cases (8%): one with conventional platinum therapy and another with irinotecan plus platinum. In group B, three cases (6%) responded: two with platinum plus etoposide and one case with irinotecan plus platinum. Median overall survival was 16 months in group A and 7 months in group B (P = 0.04). These findings suggest recurrent or resistant CCC is extremely chemoresistant, and there is only small benefit of long treatment-free period in CCC patients. Another strategy including molecular-targeting therapy is warranted for the treatment of recurrent or refractory CCC.

We conducted study to determine whether and how the expression of the hypoxia-inducible factor 1alpha (HIF-1alpha) gene relates to outcome in patients with epithelial ovarian cancer. A total of 66 patients with epithelial ovarian cancer, who underwent primary surgery followed by platinum-based chemotherapy, were entered into this study. We confirmed the expression of HIF-1alpha and the vascular endothelial growth factor (VEGF) by immunohistochemistry. To determine the quantity of HIF-1alpha and VEGF expression, messenger RNA of each gene was measured by real-time reverse transcription-polymerase chain reaction. The cutoff values were determined by the receiver-operating characteristic curve according to survival. The protein expressions of HIF-1alpha and VEGF were strongly observed in the cancer cells. The cutoff value of HIF-1alpha and VEGF gene expression was 6.0 and 3.0, respectively. The expression of HIF-1alpha did not relate to clinical stage, but tumor with low VEGF expression was observed more frequently in stage I patients. The response rate to chemotherapy did not differ between high and low expression of both genes. The overall survival for patients with high expression of HIF-1alpha was significantly lower, but disease-free survival did not differ between high and low expression of HIF-1alpha, whereas both overall and disease-free survival for patients with high expression of VEGF were significantly lower. Multivariate analysis revealed that FIGO stage and HIF-1alpha expression were independent prognostic factors but that VEGF was not. The present study suggested that the expression level of HIF-1alpha could be an independent prognostic factor in epithelial ovarian cancer.

Paclitaxel (PTX), one of the key drugs used to treat ovarian cancer, activates the Raf-mitogen-activated protein kinase kinase (MEK) and phosphatidylinositol 3'-kinase (PI3K) pathways, both considered to be proliferation and cell-survival pathways. The present study aimed to clarify whether and how MEK and PI3K inhibitors affect sensitivity to PTX in ovarian cancer cells. We treated five ovarian cancer cell lines using PTX combined with MEK inhibitor (PD98059 [PD]) and PI3K inhibitor (LY294002 [LY]), then assessed cell viability, apoptosis, and expression of phosphorylated (p) MEK and pAkt. We also investigated the effect of combined treatment on survival in a xenograft model. The protein expression levels of MEK, pMEK, Akt, and pAkt were confirmed in all cell lines. pMEK levels increased after PTX treatment in all five ovarian cancer cell lines. Combining PTX with either PD or LY had an additive effect on cell-growth inhibition. In contrast, we observed a synergistic effect when PTX was combined with both PD and LY. The number of apoptotic cells was significantly higher after treatment with PTX combined with PD and LY, compared with PTX alone or PTX with either PD or LY (P < 0.05). PD with PTX downregulated the protein expression level of pMEK and upregulated pAkt in all five cell lines. Treating nude mice with PTX and PD and LY prolonged survival in an ovarian cancer xenograft model (P < 0.005). These results indicate that further study is warranted for PTX combined with MEK inhibitor and PI3K inhibitor to treat ovarian carcinoma.

Our previous findings suggested that lower cell proliferation of clear cell carcinoma (CCC) of the ovary may contribute to its resistance to chemotherapy. We conducted the present study to find the gene that regulates cell proliferation of CCC and to elucidate whether it contributes to cisplatin (CDDP) resistance. Complementary DNA microarray analysis revealed that the gene expression level of galectin-3 of CCC cell lines (KK, RMG-I, HAC-2) was over threefold higher than that of ovarian serous adenocarcinoma (SAC) cell lines (HRA, KF). S-phase fraction increased after knocking down galectin-3 using small interfering RNA in RMG-I, KK, and HAC-2 cells. The protein expression of p27 decreased after knocking down galectin-3. CDDP-induced apoptosis was increased after knocking down galectin-3, and this cytotoxic effect was canceled by roscovitine. Immunohistochemical staining showed that galectin-3 expression in tumors of 20 CCC was significantly more frequent than that of 20 SAC (70.0% vs 15.0%, P = 0.0004). The present study showed that the expression of galectin-3 in CCC might contribute to its lower cell proliferation and lead to CDDP resistance.

We conducted the present study to investigate whether and how chemosensitivity can be determined by means of genetic diagnosis using drug-resistance genes in patients with epithelial ovarian cancer. A total of 75 patients who had epithelial ovarian cancer with measurable lesions were entered into this study. Thirty-three patients received first-line chemotherapy, consisting of paclitaxel and carboplatin (TJ). Forty-two patients received second-line chemotherapy, 22 received EP therapy consisting of etoposide and cisplatin (CDDP), and 20 received irinotecan (CPT-11) and CDDP (CPT-11/CDDP) therapy. Tumor samples were obtained before chemotherapy. MessengerRNA expressions of the multidrug-resistance (MDR)-1 gene, MDR-associated protein-1 (MRP-1), topoisomerase (topo) I, and topo IIalpha were measured by real-time reverse transcription-polymerase chain reaction. The cutoff values of each gene were determined by the receiver operating characteristic curve. MDR-1 expression was significantly higher in patients who did not respond to TJ therapy. The expression of topo IIalpha was significantly higher in patients who did respond to EP therapy. The expression of topo I was significantly higher in patients who did respond to CPT-11/CDDP. MRP-1 expression did not differ between responders and nonresponders in all regimens. The cutoff value was 80 for MDR-1, 90 for topo IIalpha, and 200 for topo I. Next, to evaluate genetic diagnosis, 31 patients were newly added. The accuracy of this genetic diagnosis for chemosensitivity was 85.7% for TJ, 77.8% for EP, and 100.0% for CPT-11/CDDP therapy. The present study suggests that genetic diagnosis may be useful to determine chemosensitivity in patients with epithelial ovarian cancer.

Background: The present study was conducted to determine the frequency and clinicopathological features of ovarian metastasis in a large population of patients with stage Ib-IIb cervical cancer., Methods: The study population consisted of 3471 patients with stage Ib to IIb cervical cancer who underwent radical hysterectomy, including pelvic lymphadenectomy and bilateral salpingo-oophorectomy, at our six institutions between 1981 and 2000. To our knowledge, this study is the largest review of patients with ovarian metastasis from cervical cancer. We reviewed the patients' medical records to determine clinicopathological features., Results: Fifty-two patients (1.50%) had ovarian metastases: 6 in stage Ib1, 12 in stage Ib2, 5 in stage IIa, and 29 in stage IIb. The mean age of patients with ovarian metastasis was 49.9 years (range: 29-73 years). The incidence of ovarian metastasis in patients with cervical cancer was 0.22% for stage Ib, 0.75% for stage IIa, and 2.17% for stage IIb with squamous cell carcinoma, and 3.72%, 5.26%, and 9.85%, respectively, in adenocarcinoma. Ovarian metastasis occurred more frequently among patients with adenocarcinoma than among those with squamous cell carcinoma (5.31% vs. 0.79%). Outcome for patients with ovarian metastasis was very poor and not related to FIGO stage and histological type. The presence of ovarian metastasis did not correlate with lymph node involvement or parametrial invasion., Conclusion: Study results indicate that ovaries can be preserved in patients with stage Ib-IIa squamous cell carcinoma but removed in all patients with adenocarcinoma.

We conducted the present study to determine the outcome of patients with early ovarian cancer who underwent three courses of adjuvant chemotherapy after complete surgical staging. One hundred consecutive patients with stage I-II epithelial ovarian cancer who had undergone complete surgical staging and received three courses of platinum-based chemotherapy were entered in this study. Twenty-one patients were low risk, defined as stage IA-B, grade 1 and histologic types except for clear cell adenocarcinoma, and remaining 79 were high risk. All patients with stage IA or IB, whatever histologic type and histopathologic grade, were alive without disease. The 5-year survival rate was 89.4% for patients with stage IC and 76.2% for those with stage II. The 5-year survival rate for low- and high-risk patients was 100% and 89.4%, respectively. The survival rate for grade 1 was significantly better than that for grade 2 or 3. Multivariate analysis revealed that histologic grade was an independent prognostic factor in stage IC-II ovarian cancer. The outcome of patients with early ovarian cancer undergoing three courses of chemotherapy after complete surgical staging was favorable even in high-risk patients.

We report on a 45-year-old patient with stage IIIc ovarian cancer, multiple brain metastases, and meningitis carcinomatosa. After three courses of initial chemotherapy, consisting of docetaxel and carboplatin, the patient underwent interval cytoreductive surgery, consisting of hyster-ectomy, bilateral salpingo-oophorectomy, omentectomy, appendectomy, and retroperitoneal lymphadenectomy. Then five courses of the same chemotherapy were given as adjuvant treatment. At the completion of the primary therapy, she achieved a complete remission. Ten months after the completion of the initial treatment, multiple brain metastases with meningitis carcinomatosa were detected. After four courses of the same chemotherapy, she again had a complete response, confirmed by cranial enhanced magnetic resonance imaging (MRI), and she felt well, with relief from the debilitating neurologic symptoms for 4 months. After this 4 months, her disease recurred, with meningitis carcinomatosa, and she requested supportive care only. She died 4 months after this recurrence. Chemotherapy can help to prolong life for some patients with multiple brain metastases and meningitis carcinomatosa from ovarian cancer.

Purpose: The aim of this study was to determine the behavior of docetaxel (DTX) in ovarian cancer cells resistant to paclitaxel (PTX)., Methods: We used human ovarian adenocarcinoma cell lines KF, KFTx (PTX-resistant KF), SK-OV-3, and HAC-2. The sensitivity of the cells to PTX or DTX was determined by the MTT assay. Cellular accumulation of PTX and DTX was measured by high-performance liquid chromatography. mRNA of MDR-1 was detected by RT-PCR. Cell cycle distribution was determined by flow cytometry after exposure to the IC(50) of each drug. Bcl-2 phosphorylation was determined by Western blot analysis. Activity for tubulin polymerization of each drug was examined by a beta-tubulin polymerization assay., Results: KFTx cells had a 5.5-fold greater resistance to PTX and a 7.3-fold greater resistance to DTX than KF cells, indicating that KFTx cells had acquired cross-resistance to DTX. SK-OV-3 cells were sensitive and HAC-2 cells were resistant to both PTX and DTX. The gene expression of MDR-1 increased after exposure to DTX in KF and KFTx cells. Residual cellular accumulation of PTX and DTX was significantly lower in KFTx cells than in KF cells. In contrast, MDR-1 expression was not detected in SK-OV-3 and HAC-2 cells. Flow cytometric analysis indicated no differences in alterations of cell cycle distribution following exposure to the two drugs. Bcl-2 phosphorylation occurred after exposure to DTX at a concentration equivalent to the clinical dose, but did not occur after exposure to PTX in KFTx cells. In HAC-2 cells, Bcl-2 phosphorylation was not detected after exposure to DTX or PTX at concentrations equivalent to the clinical doses. DTX showed greater tubulin polymerization activity than PTX in KFTx cells. beta-tubulin polymerization did not correlate with the concentration of PTX or DTX, suggesting that alteration in the tubulin reaction might contribute to the resistance in HAC-2 cells., Conclusions: The present study suggests that the mechanisms involved in cytotoxicity of and resistance to PTX and DTX do not differ, but DTX has a greater cytotoxic potential in PTX-resistant cells with an efflux system.

Background: The risk of ovarian cancer increases in women with a long history of ovarian endometriosis, particularly in postmenopausal women. We present here a case of malignant transformation of endometriosis occurring over a short time in a young woman., Case: The 27-year-old woman underwent laparoscopic cystectomy and was diagnosed with left ovarian endometrioma with an accompanying high level of serum CA125 (734.6 U/mL). Fourteen months later, she underwent cytoreductive surgery for her ovarian cancer. Histological examination revealed endometrioid adenocarcinoma with transitions between endometriosis and adenocarcinoma. She was diagnosed as having stage IIIc of ovarian cancer with paraaortic lymphnode involvement., Conclusion: We suggest that endometrial cyst of the ovary associated with high levels of serum CA125 should be managed with special care even in a young woman.

Objective: To determine whether combination treatment consisting of p53 gene transfer and cisplatin (CDDP) improves prognosis of ovarian cancer patients with peritonitis carcinomatosa, we tried this therapy in a peritonitis carcinomatosa model that we developed., Methods: A human ovarian adenocarcinoma cell line, HRA, which has homozygous deletion of the p53 gene, was used. For p53 gene transfection, we used a recombinant adenovirus carrying a wild-type p53 gene (AxCAp53). To determine the efficiency of the recombinant adenovirus to transduce HRA cells, the cells were infected with AxCALacZ, and the transduced cells were detected by beta-galactosidase staining. The expression of the p53 protein was monitored by Western blot analysis up to 15 days after infection of 50 MOI AxCAp53. The combination effect of AxCAp53 and CDDP was evaluated by 3-(4, 5-dimethelthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. Apoptotic cells were assessed morphologically by staining with Hoechst 33258. For the peritonitis carcinomatosa model in this study, we used severe combined immunodeficiency mice with an intraperitoneal injection of HRA cells., Results: The p53 protein was expressed at 24 h after infection with AxCAp53 and disappeared on the 14th day. The present in vitro study showed that wild-type p53 gene transduction significantly enhanced sensitivity to CDDP and the apoptotic index in HRA cells. A significant survival advantage was observed in the combination treatment of AxCAp53 and CDDP compared with single treatments. However, the repetitious treatment did not show significant survival advantage in the long term., Conclusion: The present study suggests that intraperitoneal treatment with AxCAp53 and CDDP is potentially useful as an adjuvant therapeutic modality for peritonitis carcinomatosa, although further study is needed to improve the long-term survival for those patients., (©2001 Elsevier Science.)