Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for gastric cancer with intraoperative detection of limited peritoneal metastasis: a Phase II study of CLASS-05 trial.

Background: Systemic chemotherapy for gastric cancer with peritoneal metastasis has limited clinical benefit; for those with intraoperative detection of occult peritoneal metastasis, cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is an alternative treatment. However, the feasibility and effects of this modality and criteria for selecting suitable groups remain unclear. This study aimed to explore the safety and efficacy of laparoscopic cytoreductive surgery (L-CRS) followed by HIPEC in gastric cancer with limited peritoneal metastasis, and this study also aimed to determine the optimized cut-off of the peritoneal cancer index. Methods: Between March 2017 and November 2019, patients diagnosed with gastric cancer peritoneal metastases by using laparoscopy and the Sugarbaker peritoneal cancer index of ≤12 were eligible for inclusion. All patients received L-CRS (including gastrectomy with D2 lymph node dissection) and resection of visible peritoneal metastasis, followed by post-operative HIPEC, and systemic chemotherapy. The primary end points were median progression-free survival and median survival time, and the secondary outcomes were morbidity and mortality within 30 days after surgery. Results: Thirty patients were eligible for analysis, of whom 19 (63.3%) were female, and the overall mean age was 53.0 years. The post-operative morbidity was 20% and the severe complication rate was 10%. The median survival time was 27.0 months with a 2-year overall survival rate of 52.3% and median progression-free survival was 14.0 months with a 2-year progression-free survival of 30.4%. Conclusions: L-CRS followed by HIPEC can be safely performed for gastric cancer with limited peritoneal metastasis and potential survival benefits.