Phase II clinical trial of sequential treatment with systemic chemotherapy and intraperitoneal paclitaxel for gastric and gastroesophageal junction peritoneal carcinomatosis - STOPGAP trial

BACKGROUND: Studies from Asia indicate that normothermic intraperitoneal chemotherapy (NIPEC) may confer survival benefit in patients with gastric peritoneal carcinomatosis (PC). However, data regarding this approach is lacking in western population. The current STOPGAP trial is intended to assess 1-year progression-free survival benefit of sequential systemic chemotherapy and paclitaxel NIPEC in patients with gastric/ gastroesophageal junction (GEJ) adenocarcinoma PC. METHODS: This is a prospective, single center, single arm, phase II investigator-initiated clinical trial. Patients with histologically proven gastric/GEJ (Siewert 3) adenocarcinoma with positive peritoneal cytology or PC will be eligible to participate after three months of standard of care systemic chemotherapy and with no evidence of visceral metastasis on restaging scans. The primary treatment is iterative paclitaxel NIPEC with systemic paclitaxel and 5-fluorouracil, which will be administered on days1 and 8 and repeated every three weeks for 4 cycles. Patients will undergo diagnostic laparoscopy both before and after NIPEC to assess peritoneal cancer index (PCI). Patients with PCI less than or equal to 10 in whom complete cytoreduction (CRS) is feasible may opt to undergo CRS with heated intraperitoneal chemotherapy (HIPEC). The primary endpoint is 1-year progression free survival and secondary endpoints are overall survival and patient reported quality of life outcomes measured by EuroQol- 5 dimensions-5 level (EuroQol-5D-5L) questionnaire. DISCUSSION: If the sequential approach of systemic chemotherapy followed by paclitaxel NIPEC proves beneficial, then this approach could be used in larger, muti-institutional randomized clinical trial of gastric PC. TRIAL REGISTRATION: The trial was registered on 21/02/2021, under clinical trials.gov; Identifier: NCT04762953.