Docetaxel, cisplatin and S-1 (DCS) combination chemotherapy for gastric cancer patients with peritoneal metastasis: a retrospective study.

Purpose: Peritoneal metastasis (PM) in advanced or recurrent gastric cancer (AGC) is the most frequent cause of death from this disease. However, current treatments remain unsatisfactory. We previously conducted studies of docetaxel, cisplatin and S-1 (DCS) combination chemotherapy for AGC. The aim of this study was to investigate the benefits and tolerability of DCS in PM patients.
Methods: Patients were divided into three groups: patients without PM (non-PM); PM patients without ascites, or mild to moderate ascites (None-Mod); and PM patients with massive ascites (Massive). Patients received oral S-1 (40 mg/m ² b.i.d.) on days 1-14, and intravenous cisplatin (60 mg/m ² ) and docetaxel (50-60 mg/m ² ) on day 8 every 3 weeks. Drug exposure, adverse events, tumor response, progression-free and overall survival (OS) rates were evaluated.
Results: Of the 111 AGC patients who received DCS as first-line therapy, 37 cases had complicated PM, 15 of whom displayed massive ascites. The response rate for PM patients was 81.5%. Drug exposure and toxicities were not meaningfully different among the groups. The MSTs were also similar: 22.6 months for the non-PM, 21.7 months for the None-Mod PM, and 16.8 months for the Massive, respectively. Ten (27.0%) patients with PM achieved downstaging and underwent curative surgery, subsequently demonstrating an excellent MST of 28.0 months. An independent prognostic factor for OS, as revealed by multivariate analyses. was a good performance status.
Conclusion: DCS is feasible and efficacious for AGC with PM, especially when patients present with a good PS.