Abstract
BACKGROUND: Peritoneal metastasis influences prognosis and quality of life in patients with gastric cancer. The efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) as postoperative adjuvant therapy for advanced gastric cancer remains unclear. AIM: To evaluate the efficacy and safety of HIPEC plus postoperative adjuvant chemotherapy (AC) for locally advanced gastric cancer. METHODS: We analyzed 225 patients with gastric cancer who underwent radical surgery, categorized by those receiving HIPEC plus AC (HIPEC + AC group) and those receiving AC alone (AC group). Treatments were administered every other day, for a total of one to three sessions. Overall survival, disease-free survival (DFS), disease-free interval, peritoneal metastasis-free interval, and safety outcomes were compared between the groups. Survival analysis was performed using Kaplan-Meier curves with log-rank tests for group comparisons. RESULTS: In total, 225 patients with non-metastatic pathological T staging 4 gastric adenocarcinoma were included (HIPEC + AC group, n = 96; AC group, n = 129). Propensity score matching balanced between-group baseline characteristics. The incidence of treatment-related adverse reactions did not differ significantly between groups. With median follow-up durations of 68.00 months (HIPEC + AC group) and 56.00 months (AC group), the HIPEC + AC group demonstrated better 3-year DFS (69.0% vs 50.0%) and longer disease-free interval and peritoneal metastasis-free interval. Three-year overall survival did not differ significantly (74.0% vs 65.0%). The median survival was 50 months in the AC group, but remained unreached in the HIPEC + AC group (cumulative survival > 50%). CONCLUSION: HIPEC plus postoperative AC improves DFS and reduces peritoneal metastasis risk in non-metastatic pathological T staging 4 gastric adenocarcinoma without increasing adverse events, confirming its safety and efficacy in preventing recurrence and dissemination.