Search

Background: Initial chemotherapy (Initial-C) followed by surgery is a promising treatment strategy for peritoneal lavage cytology-positive gastric cancer (CY1 GC) with no other noncurative factors. The aim of this study was to investigate the survival advantage of Initial-C compared to initial surgery (Initial-S) for this disease according to the macroscopic type, which was associated with prognosis and the efficacy of chemotherapy in GC., Methods: One hundred eighty-nine patients who were diagnosed with CY1 GC with no other noncurative factors at four institutions from January 2007 to December 2018 were enrolled. The patients were divided into a macroscopic type 4 group (N = 48) and a non-type 4 group (N = 141). The influence of initial treatment on overall survival (OS) in each group was evaluated., Results: In the type 4 group, the 5-year OS rates of Initial-C (N = 35) and Initial-S (N = 13) were 11.6% and 0%, respectively (P = 0.801). The multivariate analysis could not show the survival advantage of Initial-C. In the non-type 4 group, the 5-year OS rates of Initial-C (N = 41) and Initial-S (N = 100) were 48.4% and 29.0%, respectively (P = 0.020). The multivariate analysis revealed that Initial-C was independently associated with prolonged OS (hazard ratio, 0.591; 95% confidence interval, 0.375-0.933: P = 0.023)., Conclusions: Initial-C improves the prognosis of non-type 4 CY1 GC with no other noncurative factors. On the other hand, further development of effective chemotherapeutic regimens and innovative treatment strategies are required for type 4 CY1 GC., (© 2024. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)

Background: Postoperative adjuvant chemotherapy with S-1 for 1 year (corresponding to eight courses) is the standard treatment for pathological stage II gastric cancer. The phase III trial (JCOG1104) investigating the non-inferiority of four courses of S-1 to eight courses was terminated due to futility at the first interim analysis. To confirm the primary results, we reported the results after a 5-years follow-up in JCOG1104., Methods: Patients histologically diagnosed with stage II gastric cancer after radical gastrectomy were randomly assigned to receive S-1 for eight or four courses. In detail, 80 mg/m 2 /day S-1 was administered for 4 weeks followed by a 2-week rest as a single course., Results: Between February 16, 2012, and March 19, 2017, 590 patients were enrolled and randomly assigned to 8-course (295 patients) and 4-course (295 patients) regimens. After a 5-years follow-up, the relapse-free survival at 3 years was 92.2% for the 8-course arm and 90.1% for the 4-course arm, and that at 5 years was 87.7% for the 8-course arm and 85.6% for the 4-course arm (hazard ratio 1.265, 95% CI 0.846-1.892). The overall survival at 3 years was 94.9% for the 8-course arm, 93.2% for the 4-course arm, and that at 5 years was 89.7% for the 8-course arm, and 88.6% for the 4-course arm (HR 1.121, 95% CI 0.719-1.749)., Conclusions: The survival of the four-course arm was slightly but consistently inferior to that of the eight-course arm. Eight-course S-1 should thus remain the standard adjuvant chemotherapy for pathological stage II gastric cancer., (© 2023. The Author(s) under exclusive licence to The International Gastric Cancer Association and The Japanese Gastric Cancer Association.)

Background: Surgical resection of oligo-metastasis in gastric cancer (GC) is weakly recommended for patients without other incurable factors in the Japanese GC Treatment Guidelines. While post-operative chemotherapy is the standard treatment in patients with stage II or III GC, its efficacy for resected stage IV GC is unclear. This study aimed to evaluate the efficacy of post-operative chemotherapy after curative resection of GC with oligo-metastasis., Methods: We retrospectively reviewed the medical records of patients with GC who were diagnosed with synchronous oligo-metastasis at 20 institutions in Japan between 2007 and 2012. The selection criteria were: adenocarcinoma, stage IV with oligo-metastasis at liver or lymph node without other distant metastasis, curative resection including synchronous oligo-metastasis, and no prior treatment of GC before surgery., Results: A total of 110 patients were collected. Of the 94 eligible patients, 84 underwent gastrectomy with surgical resection of oligo-metastasis (39 [41%] liver metastasis and 55, [59%] distant lymph node metastasis), followed by post-operative chemotherapy with S-1 (S1: n = 55), S1 plus cisplatin (CS: n = 22), or Others (n = 7). Moreover, 10 patients did not receive post-operative chemotherapy (Non-Cx). The median overall survival (OS) was 35.2 and 11.1 months in the post-operative chemotherapy and Non-Cx groups (hazard ratio, 3.56; 95% confidence interval, 1.74-7.30; p < 0.001), respectively. In multivariable analysis, Non-Cx and age over 70 years were identified as poor prognostic factors for OS (p < 0.05)., Conclusions: Curative resection followed by post-operative chemotherapy in patients with GC with synchronous oligo-metastasis showed favorable survival., (© 2023. The Author(s) under exclusive licence to The International Gastric Cancer Association and The Japanese Gastric Cancer Association.)

Background: Recent improvements in systemic chemotherapy have provided an opportunity for patients with stage IV gastric cancer (GC) to undergo conversion surgery (CS). The aim of this study was to evaluate the long-term outcomes of patients who underwent CS and to elucidate the prognostic factors for CS in stage IV GC., Methods: A total of 79 patients who underwent CS with the aim of R0 resection for stage IV GC at six institutions from January 2008 to July 2019 were enrolled. We retrospectively reviewed the clinicopathological data and prognosis., Results: Of the 79 patients, 23 (31.1%) had initially resectable disease (IR) before chemotherapy, defined as positive for cancer on peritoneal cytology (CY1), resectable hepatic metastasis, or para-aortic lymph node No. 16a2/b1 metastasis. Of the 56 remaining patients with primary unresectable disease, 39 had peritoneal dissemination. R0 resection was accomplished in 63 patients (79.7%). The 3-year OS rates for patients with IR and unresectable disease were 78.3% and 44.5%, respectively. Multivariate analysis showed that IR (P = 0.014) and R0 (P = 0.014) were statistically significant independent prognostic factors for favorable OS. Among patients with peritoneal dissemination alone, OS was significantly better for patients with R0 resection than for patients with R1/2 resection, with the 3-year OS rates of 65.5% and 23.1%, respectively (P = 0.011)., Conclusions: CS is a treatment option for selected patients with stage IV GC. Patients with IR and patients who achieve R0 resection may obtain a survival benefit from CS., (© 2022. The Author(s).)

Background: Indications for adjuvant chemotherapy for advanced gastric cancer are determined based on the pathological diagnosis. However, macroscopic diagnoses have been reported as predictors of peritoneal recurrence and survival. This study investigated the predictability of peritoneal recurrence and survival based on macroscopically (sT) and pathologically (pT) diagnosed serosal invasion to identify more sensitive predictors of peritoneal recurrence., Methods: This study included 396 patients who underwent R0 resection without adjuvant chemotherapy with S-1 in the JCOG0110 study. Tumor depth limited to the subserosa (SS) was defined as serosal invasion negative (T-), while tumors with serosal invasion (SE, SI) were defined as serosal invasion positive (T+). The predictability of peritoneal recurrence based on sT and pT was evaluated using the Fine and Gray model. Cox regression analyses were performed for overall survival (OS) and relapse-free survival (RFS) with sT or pT as covariates., Findings: A total of 150 patients (37.9%) were sT+ and 82 (26.3%) were pT+. Sixty-two patients (15.7%) were sT+/pT+, 88 (22.2%) were sT+/pT-, 20 (5.1%) were sT-/pT+, and 226 (57.1%) were sT-/pT-. Both sT and pT were found to be independent predictors of peritoneal recurrence, OS, and RFS. The 5-year RFS rates of sT+/pT+, sT+/pT-, sT-/pT+, and sT-/pT-patients were 45.2%, 63.6%, 55.0%, and 81.8%, respectively., Conclusion: Intraoperatively diagnosed macroscopic serosal invasion showed a similar predictive value for peritoneal recurrence as pathologically diagnosed serosal invasion. The establishment of a novel staging system incorporating macroscopic serosal invasion is recommended., Competing Interests: Declaration of competing interest MT reports lecture fees from Taiho Pharmaceutical, Chugai Pharmaceutical, Ono Pharmaceutical, Bristol-Myers Squibb, Yakult Honsha, Takeda Pharmaceutical, Eli Lilly Japan KK, Pfizer Pharmaceutical, Daiichi Sankyo, Johnson and Johnson, Medtronic Japan, Intuitive Japan, Olympus outside the submitted work. JM reports the funding from National Cancer Center, Japan and the Ministry of Labour and Welfare, Japan for the present study, and personal fees from Chugai Pharmaceutical, outside the submitted work. TS reports personal fees from Taiho Pharma, Chugai Pharma, Ono Pharma, Eli Lilly, outside the submitted work. TY reports grants from Eli Lilly japan, personal fees from MSD, BMS, Ono, Taiho, Lilly, Chugai, Pfizer, Nihon Kayaku, Terumo, Otsuka, Myarisan, EA pharma, Astra-Zeneca, Covidien, Johnson and Johnson outside the submitted work. NB received a research grant from Ono and Takeda and honorarium from Taiho, Ono, Bristol-Myers Squibb outside the submitted work. MS reports lecture fees from Taiho Pharmaceutical and Eli Lilly, travel support from Eli Lilly outside the submitted work, and has served as Chairman of the board of directors of the Japan Gastric Cancer Association and member of the Guideline committee of the Japan Gastric cancer Association during the study period. All the other authors declare no competing interests. Red lines represent serosal invasion positive and blue lines represent serosal invasion negative. The C-index was calculated using the Fine and Gray model., (Copyright © 2022 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Background: To improve the diagnostic accuracy of preoperative T staging in gastric cancer, the authors evaluated tumor-related factors that might affect the diagnosis. Materials & methods: The authors analyzed the data of cT2-4b gastric cancer patients enrolled in the prospective, multicenter JCOG1302A study. They used contrast-enhanced computed tomography to analyze the association between tumor-related factors and the diagnostic accuracy of T3-4b staging for gastric cancer. Results: Among 876 cT3-4b tumors, the diagnostic accuracy was relatively low in the lower third of the stomach compared with those in the upper or middle. A multivariable analysis revealed that accuracy was higher in the lesser curvature or entire circumference region than in other areas (p < 0.001), in macroscopic types 3/5 than in types 0/1/2 (p = 0.003) and in the undifferentiated histological type than in the differentiated type (p = 0.011). Conclusion: The authors found tumor-related factors affecting preoperative T staging by enhanced computed tomography.

Purposes: The spread of coronavirus disease 2019 (COVID-19) has affected socioeconomic and healthcare systems in many countries. Accordingly, many individuals may have canceled their annual health-check programs, including esophagogastroduodenoscopy, which would have resulted in lower numbers of newly diagnosed patients with gastric cancer in comparison to other times., Methods: Questionnaires were distributed to 62 hospitals every week from May 2020 to August 2020 (total 744) through mailing lists of the Stomach Cancer Study Group of the Japan Clinical Oncology Group. The number of patients with gastric cancer and hospital systems during the COVID-19 pandemic were surveyed., Results: In total, 74% (551 out of 744) of the questionnaires were answered and analyzed. In early May, approximately 50% of hospitals had to restrict surgical slots due to the COVID-19 pandemic. However, they gradually loosened the restrictions thereafter. The number of gastrectomies was < 80% that of the same period in the previous year, and hospitals in Tokyo were seriously affected by a 50% decrease in the number of gastrectomies., Conclusions: The number of gastrectomies was lower than that in the previous year. Further multi-center follow-up studies are required to evaluate the long-term effects of COVID-19 on the clinical outcomes of patients with gastric cancer., (© 2021. Springer Nature Singapore Pte Ltd.)

Background: Gastric cancer (GC) patients with positive peritoneal lavage cytology (CY1) and/or localized peritoneum metastasis (P1a) are defined as stage IV in the 15th edition of the Japanese Classification of Gastric Cancer. In Japan, the most common treatment for patients with CY1 and/or P1a is gastrectomy followed by postoperative chemotherapy., Patients and Methods: Subjects in this multi-institutional retrospective study were GC patients with CY1 and/or P1a who received surgical resection that leaves no macroscopically visible disease. Patients were selected from 34 institutions in Japan between 2007 and 2012. Selection criteria included adenocarcinoma, no distant metastasis except CY1 and P1a, and no prior treatment for GC before surgery., Results: Among 824 patients registered, 506 were identified as eligible, with a background of P0CY1, P1aCY0, or P1aCY1 (72.5%, 16.0%, and 11.5% of subjects, respectively). Sixty-two patients had not received postoperative chemotherapy (no-Cx), whereas 444 patients had received postoperative chemotherapy: S-1 monotherapy (S-1; n = 267, 52.7%), cisplatin plus S-1 (CS; n = 114, 22.5%), and others (n = 63, 12.6%). Overall survival (OS) was 29.5, 24.7, 25.4 and 9.9 months in the S-1, CS, 'others', and no-Cx groups, respectively [CS vs. S-1: hazard ratio (HR) 1.15, 95% confidence interval (CI) 0.89-1.50; p = 0.275]. In multivariate analysis, OS was similar between the S-1 and CS groups (CS vs. S-1: HR 1.19, 95% CI 0.92-1.55; p = 0.18)., Conclusions: Postoperative chemotherapy after gastrectomy that leaves no macroscopically visible disease may have some survival benefits for GC patients with CY1 and/or P1a. In contrast, S-1 plus cisplatin seems to have no additional benefit over S-1 treatment alone.

Background: Postoperative adjuvant chemotherapy with S-1 for 1 year (corresponding to eight courses) is standard care for stage II gastric cancer. Whether the duration of S-1 could be shortened to 6 months (corresponding to four courses) without worsening survival is unclear. The aim of this study was to investigate the non-inferiority of four courses of S-1 compared with eight courses of S-1 for patients with stage II gastric cancer., Methods: We did a phase 3, open-label, randomised controlled, non-inferiority trial at 59 hospitals in Japan. Patients aged 20-80 years with stage II adenocarcinoma of the stomach were randomly assigned (1:1) to eight courses or four courses of S-1. Randomisation was done by the Japan Clinical Oncology Group Data Center website, using a minimisation method with a random component using institution, stage (IIA vs IIB), age (<70 years vs ≥70 years), and mode of operation (open gastrectomy with bursectomy vs open gastrectomy without bursectomy vs laparoscopic gastrectomy) as adjustment factors. One course was 80 mg/day per m 2 of S-1 administered for 4 weeks followed by a rest for 2 weeks. The primary endpoint was relapse-free survival, analysed by intention to treat, with a non-inferiority margin for the hazard ratio (HR) set at 1·37. This study is registered at UMIN-Clinical Trial Registry, number UMIN000007306., Findings: Between Feb 16, 2012, and March 19, 2017, 590 patients were enrolled (295 per group). 528 (89%) patients were analysed at the first planned interim analysis in March, 2017, at which time the point estimate of HR for the four-course group compared with the eight-course group was 2·52 (95% CI 1·11-5·77), which exceeded 1·37 and met the prespecified criteria for early termination. Predictive probability for showing non-inferiority at the final analysis was calculated to be 2·9%. The study was stopped for futility. Updated 3-year relapse-free survival analysed in May, 2017, was 93·1% (95% CI 87·8-96·1) for the eight-course group and 89·8% (84·2-93·5) for the four-course group (HR 1·84, 95% CI 0·93-3·63). The most common grade 3-4 adverse event was neutropenia, observed in 46 (16%) patients in the eight-course group and 51 (17%) patients in the four-course group., Interpretation: S-1 for 1 year should remain as standard adjuvant chemotherapy for stage II gastric cancer., Funding: Japan Agency for Medical Research and Development; the Ministry of Health, Labour and Welfare of Japan; the National Cancer Center Research and Development Fund, Japan., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Neoadjuvant chemotherapy (NAC) followed by radical surgery is a promising strategy to improve survival of patients with stage III gastric cancer, but is associated with the risk of preoperative overdiagnosis by which patients with early disease may receive unnecessary intensive chemotherapy., Methods: We assessed the validity of a preoperative diagnostic criterion in a prospective multicenter study. Patients with gastric cancer with a clinical diagnosis of T2/T3/T4, M0, except for diffuse large tumors and extensive bulky nodal disease, were eligible. Prospectively recorded clinical diagnoses (cT category, cN category) were compared with postoperative pathological diagnoses (pT category, pN category, and pathological stage). The primary endpoint was the proportion of pathological stage I tumors among those diagnosed as cT3/T4, which we expected to be 5% or less., Results: Data from 1260 patients enrolled from 53 institutions were analyzed. The proportion of pathological stage I tumors in those with a diagnosis of cT3/T4 (primary endpoint) was 12.3%, which was much higher than the prespecified value. The positive predictive value and the sensitivity for pathological stage III tumors were 43.6% and 87.8% respectively. The sensitivity and specificity of contrast-enhanced CT for lymph node metastasis were 62.5% and 65.7% respectively. After exploring several diagnostic criteria, we propose, for future NAC trials in Japan, a diagnosis of "cT3/T4 with cN1/N2/N3," by which inclusion of pathological stage I tumors was reduced to 6.5%, although its sensitivity for pathological stage III tumors decreased to 64.5%., Conclusion: Clinical diagnosis of T3/T4 tumors was not an optimal criterion to select patients for intensive NAC trials because more than 10% of patients with pathological stage I disease were included. We propose the criterion "cT3/T4 and cN1/N2/N3" instead.

To reveal the proteomic background of lymph node metastasis (LNM) in gastric cancer, we performed a proteomic study of tumor and matched nontumor tissues obtained from surgically resected specimens of 22 patients with or without LNM. Using laser microdissection, we recovered specific populations of tumor and nontumor cells. We used two-dimensional difference gel electrophoresis with a large format electrophoresis apparatus to obtain protein expression profiles consisting of 3228 protein spots, and we classified them according to their expression pattern. We found that macrophage-capping protein (CapG) was up-regulated in the tumor tissues of patients with LNM, whereas it showed an equivalent expression level between nontumor and tumor tissues of patients without LNM. It was reported that CapG associated with invasion and metastasis in various malignancies. However, CapG was not investigated in gastric cancer until our study. Western blotting of the laser microdissected tissue samples confirmed up-regulation of CapG in the tumor tissues of patients with LNM. Functional assays demonstrated that CapG promoted tumor cell invasion, but not cell proliferation. The association between CapG expression and LNM is a novel finding in gastric cancer. Further investigation for a prognostic utility of CapG may lead to a risk stratification therapy for gastric cancer.

The standard treatment for T4 locally advanced gastric cancer is gastrectomy with D2 lymph node dissection followed by adjuvant chemotherapy with S-1 for 12 months; however, prognostic outcome in Stage IIIb has been insufficient. It is expected that survival is improved by preoperative treatment with a triplet regimen of docetaxel, cisplatin and S-1 (divided DCS therapy). A multicenter Phase II study has been conducted to evaluate the safety and efficacy of two courses of preoperative chemotherapy followed by gastrectomy. Fifty-five patients are required for this study. The primary endpoint of the study is pathological response rate of primary lesions. Secondary endpoints are overall survival, disease-free survival, R0 resection rate and adverse events.

Thymidine kinase (TK) and thymidylate synthetase (TS) are known to catalyse the phosphorylation of thymidine for the salvage synthesis of dTMP and the methylation of dUMP for the de novo synthesis of dTMP, respectively. High TK and TS activities and the existence of TK isozymes have been observed in rapidly proliferating tissues. In this work I measured TK, TK-isozyme and TS activities, and DNA and RNA in human gastric cancer tissue. Tissue containing gastric cancer, (well differentiated adenocarcinoma (well: n = 29), poorly differentiated adenocarcinoma (por: n = 28)), and noninvolved paired normal gastric mucosa were obtained from fresh surgical specimens. Total TK and peak A TK activity of gastric cancer increased to 184% and 299% of activity of normal gastric mucosa. TK activity of "well" was higher than that of "por". On the other hand TS activity of gastric cancer increased to 122% of activity of normal gastric mucosa. TS activity of "por" was higher than that of "well". DNA and RNA content of gastric cancer increased to 294% and 228% than that of normal gastric mucosa. But difference wasn't observed between "well" and "por". These characteristics of gastric cancer suggest its susceptibility to control by inhibition of TK and TS.

5-Fluorouracil, a potent anticancer drug, is clinically known to be more effective on a poorly differentiated gastric carcinoma than on a well-differentiated type. We investigated activities of thymidylate synthetase (TS) and thymidine kinase (TK) involved in de novo and salvage pathways, respectively, for pyrimidine nucleotide synthesis and histological features in 57 human gastric carcinomas. The average activities of TS in 28 poorly differentiated carcinomas and TK in 29 well-differentiated type were significantly increased to 128 and 166%, respectively, of those in normal gastric mucosa. The TK/TS ratio in the well-differentiated type was 1.7-fold higher than that in the poorly-differentiated type. Therefore, the de novo pathway for pyrimidine nucleotide synthesis is so predominant in a poorly differentiated carcinoma, but not in a well-differentiated type, that the potent TS inhibitor 5-FU or its derivatives are suggested to suppress the growth of the poorly-differentiated gastric carcinoma.

The effect of local hyperthermotherapy (HT) using 13.56-MHz radiofrequency (RF) capacitive heating was evaluated in 25 patients with unresectable or recurrent gastric cancer. HT was carried out once to 3 times a week for a duration of one hour at each session. Patients who underwent RF-HT frequently showed maintenance of performance status, symptomatic improvement and a reduction in tumor size. Moreover, the survival time of 9 patients who had numerous metastases to the distant peritoneum was significantly high (p less than 0.01), compared with 42 historical control patients who also had massive peritoneal dissemination, but had not received HT. The results of this study therefore indicate RF-HT to be a favorable modality in the palliative treatment of patients with far-advanced gastric cancer.