Masanori Terashima

Background: Advanced gastric cancer patients with severe peritoneal metastases, defined as massive ascites throughout the abdominal cavity and/or inadequate oral intake requiring intravenous infusion support, have been excluded from pivotal clinical trials. Methods: This phase II trial evaluated mFOLFOX6 in HER2-negative, chemotherapy-naive advanced gastric cancer patients with severe peritoneal metastases. The primary endpoint was overall survival (OS); secondary endpoints included ascites response rate among patients with massive ascites and oral intake improvement rate. A sample size of 50 was planned to detect a median OS of 9 months, with a threshold of 6 months (one-sided α = 0.05; β = 0.2). A prespecified individual patient data comparative analysis was performed using data from patients treated with 5-fluorouracil/l-leucovorin (FL) or FL plus paclitaxel (FLTAX) in JCOG1108/WJOG7312G. Results: Among 51 patients, Eastern Cooperative Oncology Group performance status was 0/1/2 in 3/40/8 patients. Median OS and progression-free survival were 7.4 (lower limit of one-sided 95% confidence interval [CI], 6.5) and 3.8 months, respectively. Among 25 patients with massive ascites, the ascites response rate was 36%. Of 33 patients with inadequate oral intake, 46% achieved improved oral intake. The most frequent grade 3–4 adverse event was neutropenia (51%), and febrile neutropenia occurred in one patient (2%). No treatment-related deaths occurred. In propensity score-weighted analysis, OS hazard ratios with mFOLFOX6 versus FL and FLTAX were 0.76 (95% CI 0.56–1.03) and 0.87 (95% CI 0.64–1.18), respectively. Conclusions: mFOLFOX6 was tolerable and may be a treatment option for advanced gastric cancer patients with severe peritoneal metastases. Clinical trial registration: jRCTs041180007.

Background Papillary adenocarcinoma (Pap) is a relatively rare histological subtype of differentiated adenocarcinoma, and its biological behavior has not been fully elucidated. The present study aimed to clarify the clinicopathological characteristics of Pap. Methods This study retrospectively included 1701 patients with differentiated-type gastric cancer who underwent gastrectomy at our institution between 2009 and 2021. Clinicopathological characteristics, recurrence patterns, and survival outcomes were compared between the two groups. Results Patients in the Pap group were older and showed higher rates of venous—and lymphatic invasion, as well as more advanced clinical and pathological stages. In the multivariate analysis of cumulative recurrence, histological type was identified as an independent predictor (HR 2.051, p = 0.037). The most common initial site of recurrence was the liver in both groups, with a significantly higher incidence observed in the Pap group (p < 0.001). In the multivariate analysis of overall survival, histological type was also identified as an independent prognostic factor (HR 1.962, p = 0.044). Conclusions Pap showed poorer survival than the Tub group, with a particularly higher incidence of liver metastasis recurrence.

Background Postoperative pancreatic fistula (POPF) is a significant complication of minimally invasive gastrectomy (MIG). This study investigated whether the preoperatively assessed left gastric vein (LGV) route on contrast-enhanced computed tomography (CT) was associated with POPF. Methods This retrospective study included patients who underwent MIG for gastric cancer from January 2017 to December 2020. Based on preoperative CT, LGV anatomy was classified into four types: Type A (dorsal to the common hepatic artery), Type B (ventral to the celiac artery), Type C (dorsal to the splenic artery), and Type D (within the lesser omentum). POPF was defined as a clinically relevant fistula based on drain amylase levels or imaging findings. Risk factors were evaluated using logistic regression analysis. Results Among 566 patients, LGV routes were Type A in 285 (50.3%), Type B in 240 (42.4%), Type C in 28 (4.9%), and Type D in 13 (2.3%). POPF occurred in 14 patients (2.5%). The incidence of POPF differed significantly among LGV types and was highest in Type C (17.9% vs. 1.7% in the other types combined, p < 0.001). All POPF events occurred after laparoscopic gastrectomy, whereas no POPF was observed after robotic gastrectomy. In multivariate analysis, Type C anatomy was the only independent risk factor for POPF. Conclusions An LGV course dorsal to the splenic artery (Type C) was associated with an increased risk of POPF after MIG. There is a possibility that robotic gastrectomy may help reduce the risk of POPF in these patients.

The modified age-adjusted Charlson Comorbidity Index (mACCI) is associated with postoperative complications and long-term survival after gastrectomy. However, whether robotic gastrectomy (RG) provides clinical advantages over laparoscopic gastrectomy (LG) in high-risk patients remains unclear. This study evaluated short- and long-term outcomes of RG compared with LG according to mACCI. A total of 1501 patients who underwent minimally invasive gastrectomy for clinical stage I-II gastric cancer between 2012 and 2021 were retrospectively analyzed. Patients were stratified by mACCI (< 4 and ≥ 4), and propensity score matching was performed within each stratum. Short-term outcomes, overall survival (OS), recurrence-free survival (RFS), and cumulative incidence of other-cause and gastric cancer-specific death were assessed. Among patients with mACCI ≥ 4, RG was associated with a lower incidence of postoperative complications than LG after matching (2.7% vs. 8.2%, P = 0.036), including pancreatic fistula (0% vs. 3.3%, P = 0.030). RG showed significantly improved OS (HR 0.485, 95% CI 0.271-0.868, P = 0.015) and RFS (HR 0.417, 95% CI 0.236-0.738, P = 0.003). Competing risk analysis demonstrated a lower incidence of other-cause death in the RG group, whereas gastric cancer-specific mortality did not differ. No significant differences were observed between approaches in patients with mACCI < 4. Robotic gastrectomy was associated with reduced postoperative complications and improved long-term outcomes in high-risk patients with substantial comorbidities. RG may represent a preferable surgical approach in this population.

With aging populations, elderly gastric cancer (GC) patients are increasing. D2 lymphadenectomy is widely accepted for advanced GC, but its efficacy and safety in elderly patients are still debated. To guide surgical decisions, we conducted a systematic review and meta-analysis evaluating optimal lymphadenectomy extent in elderly patients. A systematic review was performed in accordance with the preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension statement for reporting systematic reviews. Meta-analyses were performed regarding (i) total postoperative complications, (ii) pancreatic fistula, (iii) abdominal abscess, (iv) postoperative hospital stay, and (v) overall survival by using R software. Seven retrospective studies met eligibility criteria, including three with propensity score matching. Meta-analysis showed that complication rates (any grade) were similar, while severe complications (grade ≥ 3) tended to be lower with limited lymphadenectomy. Pancreatic fistula rates showed no significant difference, but limited lymphadenectomy was significantly associated with reduced abdominal abscess incidence (RR: 0.15, p = 0.013). Postoperative hospital stay did not differ significantly between the groups. Furthermore, no significant difference in overall survival was observed between the groups (HR: 0.94, p = 0.834). Limited lymphadenectomy may be a reasonable surgical option for elderly GC patients, as it reduces the risk of abdominal abscess without compromising long-term survival. These findings support a more tailored surgical approach based on patient age and risk profile.

Purpose: This retrospective study aimed to assess the clinical effectiveness of a multimodal perioperative care program in reducing postoperative complications in elderly patients undergoing gastrectomy for gastric cancer. Methods: Overall, 1285 patients aged ≥ 75 years who underwent curative gastrectomy were classified into pre‐program (2008–2018, n = 965) and post‐program (2020–2024, n = 320) groups. The program consisted of preoperative nutritional counseling, oral care, swallowing and physical function screening, and targeted rehabilitation. The clinical characteristics and surgical outcomes of the two groups were compared. Results: In the post‐program group, 314 patients underwent swallowing screening, with 108 receiving targeted speech–language therapy and 49 being prescribed a dysphagia diet. Physical function screening was conducted on 281 patients, with 204 receiving perioperative exercise therapy. Program implementation was significantly associated with a lower incidence of overall complications (21% vs. 40%), surgical (13% vs. 21%) and non‐surgical complications (7% vs. 17%), pneumonia (4% vs. 9%), and delirium (3% vs. 7%). Multivariate analysis revealed that the program was independently associated with a significantly decreased incidence of overall complications (odds ratio [OR]: 0.431, p < 0.001) and non‐surgical complications (OR: 0.309, p < 0.001). Meanwhile, the reduction in the incidence of surgical complications was not statistically significant (OR: 0.696, p = 0.094). Conclusions: Multimodal perioperative care program may effectively reduce postoperative complications, particularly non‐surgical complications such as pneumonia, in elderly patients with gastric cancer.

Background: Radical gastrectomy, followed by adjuvant chemotherapy has been a common practice in Japan for peritoneal lavage cytology‐positive (CY1) but peritoneal dissemination‐negative (P0) stage IV gastric cancer. This study aimed to clarify the differences in treatment outcomes between upfront surgery and preoperative chemotherapy, followed by surgery for patients with CY1P0 gastric cancer using data from Japanese patients recruited for the CONVO‐GC‐1 study. Methods: This study used data from Japanese patients with CY1P0 gastric cancer recruited for the international retrospective observational CONVO‐GC‐1 study. Gastrectomy was performed between January 1, 2001, and December 31, 2014. CY1 was cytologically confirmed. The patients were divided into two groups: upfront surgery (Sx) and preoperative chemotherapy, followed by surgery (CSx). Patient background and survival outcomes were compared between the groups. Results: Four hundred and thirty‐three patients treated at 45 Japanese institutions were analyzed. There were 306 and 127 patients in the Sx and CSx groups, respectively. The 5‐year overall survival (OS) rates were 19.2% in the Sx group and 35.9% in the CSx group, with a significant difference. When stratifying OS of the two groups by residual tumor status, the 5‐year OS rates were 43.0% in the CSx‐R0 group, 14.9% in the CSx‐R1 group, 20.7% in the Sx‐R1 group, and 0.0% in the CSx‐R2 and Sx‐R2 groups. Conclusions: In CY1P0 gastric cancer, survival was better with preoperative chemotherapy, followed by surgery than with upfront surgery. Survival was particularly favorable in patients who underwent R0 resection.

Background Positive peritoneal cytology (CY1) is classified as stage IV gastric cancer and typically treated with systemic chemotherapy. However, upfront surgery is sometimes performed when CY1 is identified intraoperatively or postoperatively and may improve long-term survival when followed by adjuvant chemotherapy. It remains unclear which patients benefit most from this approach. This study aimed to identify patient subgroups likely to achieve long-term survival with upfront surgery followed by adjuvant chemotherapy. Methods We retrospectively analyzed patients diagnosed with P0CY1 who underwent upfront surgery between 2008 and 2020. Prognostic factors for overall survival (OS) and progression-free survival were evaluated using univariate and multivariate analyses. Results A total of 147 patients were included; 65% were male, with a median age of 72 years. Macroscopic types 3 and 4 were present in 80% of patients, 91% had pathological T4 tumors, and 63% had lymph node metastasis. Total gastrectomy was performed in 54%, and 81% received adjuvant chemotherapy. Median OS was 27.0 months. Univariate analysis showed age, macroscopic type, tumor size, and adjuvant chemotherapy were significantly associated with OS. Multivariate analysis identified adjuvant chemotherapy tumor size ≥ 80 mm, and macroscopic types 1 and 2 as independent favorable prognostic factors. Among patients receiving adjuvant chemotherapy, those with macroscopic types 1 and 2 had significantly better OS (5-year OS rate: 46%) compared to types 3 and 4. Conclusions In P0CY1 gastric cancer, upfront surgery followed by adjuvant chemotherapy may result in long-term survival, particularly in patients with macroscopic types 1 and 2.