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Abstract Background HAX-1 has been described as a protein potentially involved in carcinogenesis and especially metastasis. Its involvement in regulation of apoptosis and cell migration along with some data indicating its overexpression in cancer cell lines and tumors suggests that HAX-1 may play a role in neoplastic transformation. Here we present the first systematic analysis of HAX-1 expression in several solid tumors. Methods Using quantitative RT-PCR, we have determined the mRNA levels of HAX1 splice variant I in several solid tumors. We have also analyzed by semiquantitative and quantitative RT-PCR the expression of five HAX-1 splice variants in breast cancer samples and in normal tissue from the same individuals. Quantitative PCR was also employed to analyze the effect of estrogen on HAX1 expression in breast cancer cell line. Immunohistochemical analysis of HAX-1 was performed on normal and breast cancer samples. Results The results reveal statistically important HAX1 up-regulation in breast cancer, lung cancer and melanoma, along with some minor variations in the splicing pattern. HAX-1 up-regulation in breast cancer samples was confirmed by immunohistochemical analysis, which also revealed an intriguing HAX-1 localization in the nuclei of the tumor cells, associated with strong ER status. Conclusion HAX-1 elevated levels in cancer tissues point to its involvement in neoplastic transformation, especially in breast cancer. The connection between HAX-1 nuclear location and ER status in breast cancer samples remains to be clarified.

Abstract Background PALB2 protein was recently identified as a partner of BRCA1 and BRCA2 which determines their proper function in DNA repair. Methods Initially, the entire coding sequence of the PALB2 gene with exon/intron boundaries was evaluated by the PCR-SSCP and direct sequencing methods on 70 ovarian carcinomas. Sequence variants of interest were further studied on enlarged groups of ovarian carcinomas (total 339 non-consecutive ovarian carcinomas), blood samples from 334 consecutive sporadic and 648 consecutive familial breast cancer patients, and 1310 healthy controls from central Poland. Results Ten types of sequence variants were detected, and among them four novel polymorphisms: c.2996+58T>C in intron 9; c.505C>A (p.L169I), c.618T>G (p.L206L), both in exon 4; and c.2135C>T (A712V) in exon 5 of the PALB2 gene. Another two polymorphisms, c.212-58A>C and c.2014G>C (E672Q) were always detected together, both in cancer (7.5% of patients) and control samples (4.9% of controls, p = 0.2). A novel germline truncating mutation, c.509_510delGA (p.R170fs) was found in exon 4: in 2 of 339 (0.6%) unrelated ovarian cancer patients, in 4 of 648 (0.6%) unrelated familial breast cancer patients, and in 1 of 1310 controls (0.08%, p = 0.1, p = 0.044, respectively). One ovarian cancer patient with the PALB2 mutation had also a germline nonsense mutation of the BRCA2 gene. Conclusions The c.509_510delGA is a novel PALB2 mutation that increases the risk of familial breast cancer. Occurrence of the same PALB2 alteration in seven unrelated women suggests that c.509_510delGA (p.R170fs) is a recurrent mutation for Polish population.

Abstract Background In recent years, numerous studies have investigated somatic mutations in mitochondrial DNA in various tumours. The observed high mutation rates might reflect mitochondrial deregulation; consequently, mutation analyses could be clinically relevant. The purpose of this study was to determine if mutations in the mitochondrial D-loop region and/or the level of mitochondrial gene expression could influence the clinical course of human ovarian carcinomas. Methods We sequenced a 1320-base-pair DNA fragment of the mitochondrial genome (position 16,000-750) in 54 cancer samples and in 44 corresponding germline control samples. In addition, six transcripts (MT-ATP6, MT-CO1, MT-CYB, MT-ND1, MT-ND6, and MT-RNR1) were quantified in 62 cancer tissues by real-time RT-PCR. Results Somatic mutations in the D-loop sequence were found in 57% of ovarian cancers. Univariate analysis showed no association between mitochondrial DNA mutation status or mitochondrial gene expression and any of the examined clinicopathologic parameters. A multivariate logistic regression model revealed that the expression of the mitochondrial gene RNR1 might be used as a predictor of tumour sensitivity to chemotherapy. Conclusion In contrast to many previously published papers, our study indicates rather limited clinical relevance of mitochondrial molecular analyses in ovarian carcinomas. These discrepancies in the clinical utility of mitochondrial molecular tests in ovarian cancer require additional large, well-designed validation studies.

Abstract Background Taxane-platinum therapy (TP) has replaced platinum-based therapy (PC or PAC, DNA damaging chemotherapy) in the postoperative treatment of ovarian cancer patients; however, it is not always effective. TP53 protein plays a differential role in response to DNA-damaging agents and taxanes. We sought to define profiles of patients who benefit the most from TP and also of those who can be treated with PC. Methods We compared the effectiveness of PC/PAC (n = 253) and TP (n = 199) with respect to tumor TP53 accumulation in ovarian cancer patients with FIGO stage IIB-IV disease; this was a non-randomized retrospective study. Immunohistochemical analysis was performed on 452 archival tumors; univariate and multivariate analysis by the Cox's and logistic regression models was performed in all patients and in subgroups with [TP53(+)] and without TP53 accumulation [TP53(-)]. Results The advantage of taxane-platinum therapy over platinum-based therapy was seen in the TP53(+), and not in the TP53(-) group. In the TP53(+) group taxane-platinum therapy enhanced the probability of complete remission (p = .018), platinum sensitivity (p = .014), platinum highly sensitive response (p = .038) and longer survival (OS, p = .008). Poor tumor differentiation diminished the advantage from taxane-platinum therapy in the TP53(+) group. In the TP53(-) group PC/PAC was at least equally efficient as taxane-platinum therapy and it enhanced the chance of platinum highly sensitive response (p = .010). However, in the TP53(-) group taxane-platinum therapy possibly diminished the risk of death in patients over 53 yrs (p = .077). Among factors that positively interacted with taxane-platinum therapy in some analyses were endometrioid and clear cell type, FIGO III stage, bulky residual tumor, more advanced age of patient and moderate tumor differentiation. Conclusion Our results suggest that taxane-platinum therapy is particularly justified in patients with TP53(+) tumors or older than 53 years. In the group of patients ≤53 yrs and with TP53(-) tumors platinum-based therapy is possibly equally efficient. We provide hints for planning randomized trials to verify these observations.

ERBB2 expression has been found in 19 to 44% of ovarian carcinomas; however, its predictive value has not been demonstrated, and trastuzumab has not found clinical application in ovarian cancer patients. We evaluated clinical significance of ERBB2 expression in relation to TP53 accumulation in ovarian carcinoma patients treated with platinum-based regimens. Immunohistochemical analysis with CB11 and a novel NCL-CBE356 antibody (against the internal and external domains of ERBB2, respectively) was performed on 233 tumours (FIGO stage IIB-IV); the US Food and Drug Administration-approved grading system with 0 to 3+ scale was used for evaluation, and the results were analysed by the Cox and logistic regression models. In all, 42% of the tumours expressed (category 1+, 2+ or 3+) either CB11 or CBE356 or both (CB11/CBE356 parameter). Associations between ERBB2 expression and clinical factors were observed only if tumours with staining category 1+ were grouped together with tumours showing staining categories 2+ and 3+. CB11/CBE356 parameter had a better predictive value than CB11 alone. CB11/CBE356 expression was negatively associated with platinum sensitivity (PS) in the TP53(-) group (P=0.022) and with disease-free survival (DFS) in the TP53(+) group (P=0.009). Our results may suggest that trastuzumab should be given postoperatively to patients with TP53(-)/ERBB2(+) ovarian carcinomas to enhance PS, and after completion of chemotherapy to patients with complete remission and TP53(+)/ERBB2(+) carcinomas to extend DFS time (in total to 30.4% of all patients analysed). Thus, novel criteria for ovarian cancer patient inclusion for clinical trials with trastuzumab should be considered and tested. [ABSTRACT FROM AUTHOR]

Breast, ovarian, and prostate cancers are hormone-related and may have a shared genetic basis, but this has not been investigated systematically by genome-wide association (GWA) studies. Meta-analyses combining the largest GWA meta-analysis data sets for these cancers totaling 112,349 cases and 116,421 controls of European ancestry, all together and in pairs, identified at P < 10(-8) seven new cross-cancer loci: three associated with susceptibility to all three cancers (rs17041869/2q13/BCL2L11; rs7937840/11q12/INCENP; rs1469713/19p13/GATAD2A), two breast and ovarian cancer risk loci (rs200182588/9q31/SMC2; rs8037137/15q26/RCCD1), and two breast and prostate cancer risk loci (rs5013329/1p34/NSUN4; rs9375701/6q23/L3MBTL3). Index variants in five additional regions previously associated with only one cancer also showed clear association with a second cancer type. Cell-type-specific expression quantitative trait locus and enhancer-gene interaction annotations suggested target genes with potential cross-cancer roles at the new loci. Pathway analysis revealed significant enrichment of death receptor signaling genes near loci with P < 10(-5) in the three-cancer meta-analysis., Other Research Unit

BACKGROUND: Genome-wide association studies (GWAS) have so far reported 12 loci associated with serous epithelial ovarian cancer (EOC) risk. We hypothesized that some of these loci function through nearby transcription factor (TF) genes and that putative target genes of these TFs as identified by coexpression may also be enriched for additional EOC risk associations. METHODS: We selected TF genes within 1 Mb of the top signal at the 12 genome-wide significant risk loci. Mutual information, a form of correlation, was used to build networks of genes strongly coexpressed with each selected TF gene in the unified microarray dataset of 489 serous EOC tumors from The Cancer Genome Atlas. Genes represented in this dataset were subsequently ranked using a gene-level test based on results for germline SNPs from a serous EOC GWAS meta-analysis (2,196 cases/4,396 controls). RESULTS: Gene set enrichment analysis identified six networks centered on TF genes (HOXB2, HOXB5, HOXB6, HOXB7 at 17q21.32 and HOXD1, HOXD3 at 2q31) that were significantly enriched for genes from the risk-associated end of the ranked list (P < 0.05 and FDR < 0.05). These results were replicated (P < 0.05) using an independent association study (7,035 cases/21,693 controls). Genes underlying enrichment in the six networks were pooled into a combined network. CONCLUSION: We identified a HOX-centric network associated with serous EOC risk containing several genes with known or emerging roles in serous EOC development. IMPACT: Network analysis integrating large, context-specific datasets has the potential to offer mechanistic insights into cancer susceptibility and prioritize genes for experimental characterization.

PURPOSE: Chemotherapy resistance remains a major challenge in the treatment of ovarian cancer. We hypothesize that germline polymorphisms might be associated with clinical outcome. EXPERIMENTAL DESIGN: We analyzed approximately 2.8 million genotyped and imputed SNPs from the iCOGS experiment for progression-free survival (PFS) and overall survival (OS) in 2,901 European epithelial ovarian cancer (EOC) patients who underwent first-line treatment of cytoreductive surgery and chemotherapy regardless of regimen, and in a subset of 1,098 patients treated with ≥ 4 cycles of paclitaxel and carboplatin at standard doses. We evaluated the top SNPs in 4,434 EOC patients, including patients from The Cancer Genome Atlas. In addition, we conducted pathway analysis of all intragenic SNPs and tested their association with PFS and OS using gene set enrichment analysis. RESULTS: Five SNPs were significantly associated (P ≤ 1.0 × 10(-5)) with poorer outcomes in at least one of the four analyses, three of which, rs4910232 (11p15.3), rs2549714 (16q23), and rs6674079 (1q22), were located in long noncoding RNAs (lncRNAs) RP11-179A10.1, RP11-314O13.1, and RP11-284F21.8, respectively (P ≤ 7.1 × 10(-6)). ENCODE ChIP-seq data at 1q22 for normal ovary show evidence of histone modification around RP11-284F21.8, and rs6674079 is perfectly correlated with another SNP within the super-enhancer MEF2D, expression levels of which were reportedly associated with prognosis in another solid tumor. YAP1- and WWTR1 (TAZ)-stimulated gene expression and high-density lipoprotein (HDL)-mediated lipid transport pathways were associated with PFS and OS, respectively, in the cohort who had standard chemotherapy (pGSEA ≤ 6 × 10(-3)). CONCLUSIONS: We have identified SNPs in three lncRNAs that might be important targets for novel EOC therapies., Other Research Unit

Survival in epithelial ovarian cancer (EOC) is influenced by the host immune response, yet the key genetic determinants of inflammation and immunity that impact prognosis are not known. The nuclear factor-kappa B (NF-κB) transcription factor family plays an important role in many immune and inflammatory responses, including the response to cancer. We studied common inherited variation in 210 genes in the NF-κB family in 10,084 patients with invasive EOC (5,248 high grade serous, 1,452 endometrioid, 795 clear cell, and 661 mucinous) from the Ovarian Cancer Association Consortium. Associations between genotype and overall survival were assessed using Cox regression for all patients and by major histology, adjusting for known prognostic factors and correcting for multiple testing (threshold for statistical significance—p < 2.5×10−5). Results were statistically significant when assessed for patients of a single histology. Key associations were with CARD11 (caspase recruitment domain family, member 11) rs41324349 in patients with mucinous EOC (HR 1.82, 95% CI 1.41–2.35, p=4.13×10−6) and TNFRSF13B (tumor necrosis factor receptor superfamily, member 13B) rs7501462 in patients with endometrioid EOC (HR 0.68, 95% CI 0.56–0.82, p=2.33×10−5). Other associations of note included TRAF2 (TNF receptor-associated factor 2) rs17250239 in patients with high-grade serous EOC (HR 0.84, 95% CI 0.77–0.92, p=6.49×10−5) and PLCG1 (phospholipase C, gamma 1) rs11696662 in patients with clear cell EOC (HR 0.43, 95% CI 0.26–0.73, p=4.56×10−4). These associations highlight the potential importance of genes associated with host inflammation and immunity in modulating clinical outcomes in distinct EOC histologies.

Background Ovarian cancer is a leading cause of cancer-related death among women. In an effort to understand contributors to disease outcome, we evaluated single-nucleotide polymorphisms (SNPs) previously associated with ovarian cancer recurrence or survival, specifically in angiogenesis, inflammation, mitosis, and drug disposition genes. Methods Twenty-seven SNPs in VHL, HGF, IL18, PRKACB, ABCB1, CYP2C8, ERCC2, and ERCC1 previously associated with ovarian cancer outcome were genotyped in 10,084 invasive cases from 28 studies from the Ovarian Cancer Association Consortium with over 37,000 observed person-years and 4,478 deaths. Cox proportional hazards models were used to examine the association between candidate SNPs and ovarian cancer recurrence or survival with and without adjustment for key covariates. Results We observed no association between genotype and ovarian cancer recurrence or survival for any of the SNPs examined. Conclusions These results refute prior associations between these SNPs and ovarian cancer outcome and underscore the importance of maximally powered genetic association studies. Impact These variants should not be used in prognostic models. Alternate approaches to uncovering inherited prognostic factors, if they exist, are needed.

A missense single-nucleotide polymorphism (SNP) in the immune modulatory gene IL1A has been associated with ovarian cancer risk (rs17561). Although the exact mechanism through which this SNP alters risk of ovarian cancer is not clearly understood, rs17561 has also been associated with risk of endometriosis, an epidemiologic risk factor for ovarian cancer. Interleukin-1α (IL1A) is both regulated by and able to activate NF-κB, a transcription factor family that induces transcription of many proinflammatory genes and may be an important mediator in carcinogenesis. We therefore tagged SNPs in more than 200 genes in the NF-κB pathway for a total of 2,282 SNPs (including rs17561) for genotype analysis of 15,604 cases of ovarian cancer in patients of European descent, including 6,179 of high-grade serous (HGS), 2,100 endometrioid, 1,591 mucinous, 1,034 clear cell, and 1,016 low-grade serous, including 23,235 control cases spanning 40 studies in the Ovarian Cancer Association Consortium. In this large population, we confirmed the association between rs17561 and clear cell ovarian cancer [OR, 0.84; 95% confidence interval (CI), 0.76-0.93; P = 0.00075], which remained intact even after excluding participants in the prior study (OR, 0.85; 95% CI, 0.75-0.95; P = 0.006). Considering a multiple-testing-corrected significance threshold of P < 2.5 × 10(-5), only one other variant, the TNFSF10 SNP rs6785617, was associated significantly with a risk of ovarian cancer (low malignant potential tumors OR, 0.85; 95% CI, 0.79-0.91; P = 0.00002). Our results extend the evidence that borderline tumors may have a distinct genetic etiology. Further investigation of how these SNPs might modify ovarian cancer associations with other inflammation-related risk factors is warranted., Other Research Unit

Abstract Background Survivin is an inhibitor of apoptosis and a regulator of mitotic progression. TP53 protein is a negative transcriptional regulator of survivin. The aim of our study was to evaluate the clinical significance of survivin expression in advanced stages ovarian cancer with respect to the TP53 status. Methods Survivin and TP53 expression was evaluated immunohistochemically in 435 archival samples of ovarian carcinomas (244 patients were treated with platinum/cyclophosphamide-PC/PAC; 191-with taxane-platinum (TP) agents). Univariate and multivariate statistical analyses were performed in patients groups divided according to the administered chemotherapeutic regimen, and in subgroups with and without TP53 accumulation (TP53+ and TP53-, respectively). Results Nuclear and cytoplasmic survivin expression was observed in 92% and 74% of the carcinomas, respectively. In patients treated with TP, high nuclear survivin expression decreased the risk of disease recurrence and death, and increased the probability of high platinum sensitivity (p < 0.01), but only in the TP53(+) group, and not in the TP53(-) group. Conclusions It appears that TP53 status determines the clinical importance of nuclear survivin expression in taxane-platinum treated ovarian cancer patients.

Background: Women with low-grade ovarian serous carcinoma (LGSC) benefit from surgical treatment; however, the role of chemotherapy is controversial. We examined an international database through the Ovarian Cancer Association Consortium to identify factors that affect survival in LGSC., Methods: We performed a retrospective cohort analysis of patients with LGSC who had had primary surgery and had overall survival data available. We performed univariate and multivariate analyses of progression-free survival and overall survival, and generated Kaplan-Meier survival curves., Results: Of the 707 patients with LGSC, 680 (96.2%) had available overall survival data. The patients' median age overall was 54 years. Of the 659 patients with International Federation of Obstetrics and Gynecology stage data, 156 (23.7%) had stage I disease, 64 (9.7%) had stage II, 395 (59.9%) had stage III, and 44 (6.7%) had stage IV. Of the 377 patients with surgical data, 200 (53.0%) had no visible residual disease. Of the 361 patients with chemotherapy data, 330 (91.4%) received first-line platinum-based chemotherapy. The median follow-up duration was 5.0 years. The median progression-free survival and overall survival were 43.2 months and 110.4 months, respectively. Multivariate analysis indicated a statistically significant impact of stage and residual disease on progression-free survival and overall survival. Platinum-based chemotherapy was not associated with a survival advantage., Conclusion: This multicentre analysis indicates that complete surgical cytoreduction to no visible residual disease has the most impact on improved survival in LGSC. This finding could immediately inform and change practice., Competing Interests: Competing interests: Stephanie Lheureux reports study grants from AstraZeneca, GSK and Roche, consulting fees from AstraZeneca, GSK, Roche, Novartis, Merck, Eisai Co. and Shattuck Labs, and speaker’s honororia from AstraZeneca, GSK, Eisai Co. and Merck. Line Bjørge is president of the Nordic Society of Gynaecological Oncology executive board. Anna deFazio sits on the Australia New Zealand Gynaecological Oncology Group (ANZGOG) Research Advisory Committee, the Clinical and Scientific Expert Advisory Panel of Ovarian Cancer Australia and the Scientific Advisory Committee of the Australian Gynaecological Cancer Foundation. She is chair of the Translational ANZGOG (TRANZGOG) Steering Committee, chair of the International Consortium for Low-Grade Serous Ovarian Cancer Steering Committee and chair of the ANZGOG Translational subcommittee. Michael Friedlander reports consulting fees from AstraZeneca, GSK, MSD, Eli Lilly and Company, Takeda and Novartis; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Astra-Zeneca, GSK and ACT Genomics; and support for attending meetings and/or travel from AstraZeneca. He sits on the Australasian Gastrointestinal Trial Group independent data monitoring committee and is a Steering Committee member for Abbvie’s VELIA trial. Catherine Kennedy is a member of the International Society for Biological and Environmental Repositories Science Policy Committee and of the Australasian Biospecimen Network (ABNA) Management Committee. She is past president and treasurer of ABNA. Liv Cecilie Vestrheim Thomsen reports grants from AstraZeneca, and payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Bayer and AstraZeneca. She sits on an advisory board for Eisai Co. Ignace Vergote reports consulting fees from Deciphera Pharmaceuticals, Jazz Pharmaceuticals and Oncoinvent AS, and payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Agenus, AkseBio, AstraZeneca, Bristol Myers Squibb, Deciphera Pharmaceuticals, Eisai Co., F. Hoffmann-La Roche, Genmab, GSK, ImmunoGen, Jazz Pharmaceuticals, Karyopharm Therapeutics, MSD, Novocure, Novartis, Oncoinvent AS, Seagen and Sotio Biotech. He sits on a data safety monitoring board or advisory board for Agenus, AstraZeneca, Bristol Myers Squibb, Deciphera Pharmaceuticals, Eisai Co., F. Hoffmann-La Roche, Genmab, GSK, ImmunoGen, MSD, Novocure, Novartis, Seagen and Sotio Biotech. Penelope Webb reports a speaker’s honorarium from AstraZeneca. No other competing interests were declared., (© 2023 CMA Impact Inc. or its licensors.)

Ovarian cancer (OC) is usually diagnosed late due to its nonspecific symptoms and lack of reliable tools for early diagnostics and screening. OC studies concentrate on the search for new biomarkers and therapeutic targets. This study aimed to validate the MFAP5 gene, and its encoded protein, as a potential prognostic biomarker. In our previous study, we found that patients with high-grade serous OC who had higher MFAP5 mRNA levels had shorter survival, as compared with those with lower levels. Here, we used the Kaplan-Meier Plotter and CSIOVDB online tools to analyze possible associations of MFAP5 expression with survival and other clinico-pathological features. In these analyses, higher MFAP5 mRNA expression was observed in the more advanced FIGO stages and high-grade tumors, and was significantly associated with shorter overall and progression-free survival. Next, we analyzed the expression of the MFAP5 protein by immunohistochemistry (IHC) in 108 OC samples and tissue arrays. Stronger MFAP5 expression was associated with stronger desmoplastic reaction and serous vs. non-serous histology. We found no significant correlation between IHC results and survival, although there was a trend toward shorter survival in patients with the highest IHC scores. We searched for co-expressed genes/proteins using cBioPortal and analyzed potential MFAP5 interaction networks with the STRING tool. MFAP5 was shown to interact with many extracellular matrix proteins, and was connected to the Notch signaling pathway. Therefore, although not suitable as a prognostic biomarker for evaluation with a simple diagnostic tool like IHC, MFAP5 is worth further studies as a possible therapeutic target.

Objective: The main goal of fertility-sparing treatment is pregnancy followed by live birth (i.e., successful pregnancy). The principal objective of our study was to evaluate the successful pregnancy rate in patients with borderline ovarian tumors (BOTs) after conservative treatment. The second goal was to evaluate the safety of the conservative approach., Study Design: 110 patients with BOT were retrospectively evaluated. All patients underwent surgical treatment, sparing the uterus and part of at least one ovary., Results: The median age was 28 years (range 17-40 years). Serous and mucinous tumors were found in 63 (57%) and 34 (31%) women, respectively. FIGO stage I, II, and III was diagnosed in 101 (91.8%), 3 (2.7%), and 6 (5.5%) patients, respectively. The 3- and 5-year progression-free survival was 82.5% and 78.2%, respectively. Recurrent disease was treated conservatively in 14 women, whereas 3 patients underwent radical surgery. Fifty-six (50.9%) patients got pregnant and had at least one live birth. A total of 83 children were born. A significant difference in the successful pregnancy rate was found in patients diagnosed ≤ 35 years vs. > 35 years old (55.6% vs. 9.1%, respectively; p = 0.003). Surgical approach (laparoscopy vs. laparotomy) did not influence the chance of childbirth. Pre-term delivery constituted 6.25% of all births., Conclusions: Fertility-sparing surgery should be proposed to young women wishing to preserve fertility. The rate of spontaneous pregnancy is approximately 50%.The risk of relapse is significant but always of borderline histology and may be successfully treated by the second surgery., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Previously, based on a DNA microarray experiment, we identified a 96-gene prognostic signature associated with the shorter survival of ovarian cancer patients. We hypothesized that some differentially expressed protein-coding genes from this signature could potentially serve as prognostic markers. The present study was aimed to validate two proteins, namely fibronectin (FN1) and periostin (POSTN), in the independent set of ovarian cancer samples. Both proteins are mainly known as extracellular matrix proteins with many important functions in physiology. However, there are also indications that they are implicated in cancer, including ovarian cancer. The expression of these proteins was immunohistochemically analyzed in 108 surgical samples of advanced ovarian cancer (majority: high-grade serous) and additionally on tissue arrays representing different stages of the progression of ovarian and fallopian tube epithelial tumors, from normal epithelia, through benign tumors, to adenocarcinomas of different stages. The correlation with clinical, pathological, and molecular features was evaluated. Kaplan-Meier survival analysis and Cox-proportional hazards models were used to estimate the correlation of the expression levels these proteins with survival. We observed that the higher expression of fibronectin in the tumor stroma was highly associated with shorter overall survival (OS) (Kaplan-Meier analysis, log-rank test p = 0.003). Periostin was also associated with shorter OS ( p = 0.04). When we analyzed the combined score, calculated by adding together individual scores for stromal fibronectin and periostin expression, Cox regression demonstrated that this joint FN1&POSTN score was an independent prognostic factor for OS (HR = 2.16; 95% CI: 1.02-4.60; p = 0.044). The expression of fibronectin and periostin was also associated with the source of ovarian tumor sample: metastases showed higher expression of these proteins than primary tumor samples (χ 2 test, p = 0.024 and p = 0.032). Elevated expression of fibronectin and periostin was also more common in fallopian cancers than in ovarian cancers. Our results support some previous observations that fibronectin and periostin have a prognostic significance in ovarian cancer. In addition, we propose the joint FN1&POSTN score as an independent prognostic factor for OS. Based on our results, it may also be speculated that these proteins are related to tumor progression and/or may indicate fallopian-epithelial origin of the tumor.

Purpose: Ovarian cancer is typically diagnosed at late stages, and thus, patients' prognosis is poor. Improvement in treatment outcomes depends, at least partly, on better understanding of ovarian cancer biology and finding new molecular markers and therapeutic targets., Methods: An unsupervised method of data analysis, singular value decomposition, was applied to analyze microarray data from 101 ovarian cancer samples; then, selected genes were validated by quantitative PCR., Results: We found that the major factor influencing gene expression in ovarian cancer was tumor histological type. The next major source of variability was traced to a set of genes mainly associated with extracellular matrix, cell motility, adhesion, and immunological response. Hierarchical clustering based on the expression of these genes revealed two clusters of ovarian cancers with different molecular profiles and distinct overall survival (OS). Patients with higher expression of these genes had shorter OS than those with lower expression. The two clusters did not derive from high- versus low-grade serous carcinomas and were unrelated to histological (ovarian vs. fallopian) origin. Interestingly, there was considerable overlap between identified prognostic signature and a recently described invasion-associated signature related to stromal desmoplastic reaction. Several genes from this signature were validated by quantitative PCR; two of them-DSPG3 and LOX-were validated both in the initial and independent sets of samples and were significantly associated with OS and disease-free survival., Conclusions: We distinguished two molecular subgroups of serous ovarian cancers characterized by distinct OS. Among differentially expressed genes, some may potentially be used as prognostic markers. In our opinion, unsupervised methods of microarray data analysis are more effective than supervised methods in identifying intrinsic, biologically sound sources of variability. Moreover, as histological type of the tumor is the greatest source of variability in ovarian cancer and may interfere with analyses of other features, it seems reasonable to use histologically homogeneous groups of tumors in microarray experiments.