Prophylactic hyperthermic intraperitoneal chemotherapy for patients with clinical T4 gastric cancer

Patients with clinical T4 gastric cancers have high recurrence rates and low 5-year overall survival (OS) despite radical gastrectomy with D2 lymphadenectomy and adjuvant chemotherapy. The invisible peritoneal metastasis may result in local recurrence due to the tumor invading the serosa and nearby organs. Prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) has been suggested as an adjuvant treatment strategy in these patients. We evaluated the efficacy of prophylactic HIPEC post-gastrectomy for patients with clinical T4 gastric cancer.We retrospectively reviewed data from 132 patients with clinical T4 gastric cancer who underwent gastrectomy + D2 lymphadenectomy between 2014 and 2020. Thirty-five of these patients also underwent prophylactic HIPEC perioperatively. We used propensity score matching (PSM) to reduce selection bias. We evaluated the risk factors for recurrence and compared the OS and disease-free survival (DFS) between the gastrectomy and prophylactic HIPEC groups.A total of 132 eligible patients were included in the study. Seventy preoperative patient characteristics were homogeneous post-PSM. Prophylactic HIPEC seemed to reduce the risk of postoperative peritoneal recurrence but did not influence the risk of distant metastasis. The risk factors for recurrence included advanced N stage, ascites, and lymphovascular invasion. OS (adjusted hazard ratio, 0.37; 95% CI, 0.17 to 0.81; p = 0.035) and DFS (adjusted hazard ratio, 0.33; 95% CI, 0.15 to 0.72; p = 0.017) were better in the prophylactic HIPEC group than in the gastrectomy alone group.Prophylactic HIPEC plus radical gastrectomy can reduce peritoneal recurrence and improve OS and DFS in patients with clinical T4 gastric cancer.