Phase I Trial of Hyperthermic Intraperitoneal Chemoperfusion (HIPEC) with Cisplatin, Mitomycin, and Paclitaxel in Patients with Gastric Adenocarcinoma and Associated Carcinomatosis or Positive Cytology

Background: The purpose of this phase I trial is to evaluate the safety and toxicity of laparoscopic hyperthermic intraperitoneal perfusion with chemotherapy (HIPEC), combining mitomycin, cisplatin, and paclitaxel for patients with gastric cancer metastatic to the peritoneum. Patients and Methods: A Bayesian optimal interval design was used to prospectively identify the safety and tolerability of escalating doses of paclitaxel in combination with flat doses of mitomycin (30 mg) and cisplatin (200 mg) during laparoscopic HIPEC. The primary objective is to define the maximum tolerated dose. Secondary endpoints include surgical complications and overall survival (OS). Results: A total of 27 patients were treated between 11/2017 and 11/2018. No dose-limiting toxicities were observed. Treatment-related grade 1–2 toxicities were leukopenia (11%), oral dysesthesia (4%), arthralgia (4%), and diarrhea (4%). Treatment-related grade 3–4 toxicities included leukopenia (4%) and neutropenia (4%). The maximum dose for paclitaxel was 60 mg/m². Rates of Clavien–Dindo surgical complications were grade I 96% (all electrolyte deficiencies requiring replacement), II 4%, III 0%, IV 0%, and V 4%. The median follow-up time was 15 months. One- and 2-year OS rates from date of metastatic disease were 73.9% and 58.1%, respectively. Conclusions: Laparoscopic HIPEC with mitomycin, cisplatin, and paclitaxel may be safely used at intraperitoneal doses of 30 mg, 200 mg, and 60 mg/m², respectively. Although electrolyte abnormalities were common, systemic toxicity was low. Survival rates were promising, supporting further research into intraperitoneal therapy for stage IV gastric cancer.