Treatment Modality Based Survival in Gastric Carcinoma Patients with Stand-Alone Peritoneal Metastasis: a Case-Control Study

Purpose: To date, there are no promising treatments for gastric carcinoma with peritoneal metastasis. Some researchers have suggested a survival benefit of gastrectomy in select patients. This study investigated the survival of gastric carcinoma patients with stand-alone peritoneal metastasis according to the type of treatment modality. Materials and Methods: We reviewed the data of 132 patients with gastric carcinoma and stand-alone peritoneal metastasis. We performed gastrectomy when the primary tumor was deemed resectable and systemic chemotherapy was administered. We analyzed patient survival according to the type of treatment, and the prognostic value of gastrectomy was evaluated in univariate and multivariate models. Results: Among all patients, 70 underwent gastrectomy plus chemotherapy, 20 underwent gastrectomy alone, 36 underwent chemotherapy alone, and 6 received supportive care. The median patient survival was 13 months. Patients who underwent gastrectomy had significantly longer survival than those who did not undergo gastrectomy (14 vs. 8 months, P<0.001). Patients who received chemotherapy showed significantly longer survival than those who did not (13 vs. 7 months, P=0.032). Patients who underwent gastrectomy plus chemotherapy showed better survival than those who underwent other treatments. In multivariate analysis, gastrectomy was found to be an independent prognostic factor (hazard ratio, 0.52; 95% confidence interval, 0.33-0.82) in addition to chemotherapy. Conclusions: Our study showed that patients who underwent gastrectomy plus chemotherapy had the best survival. Although the survival benefit of gastrectomy remains uncertain, it is a favorable prognostic indicator in patients with stand-alone peritoneal metastasis.