Gross Appearance and Curability Are Predictive Factors of a Better Prognosis After Gastrectomy in Gastric Cancer Patients with Metastasis to the Adjacent Peritoneum of the Stomach

[Background] Gastric cancer patients with peritoneal metastasis have an extremely poor prognosis. The aim of the current study was to clarify the predictive factors of a better outcome in gastric cancer patients with peritoneal metastasis. [Methods] We analyzed the records of 2262 gastric adenocarcinoma patients who underwent gastrectomies at our institution between January 1980 and December 2010. [Results] The 5-year survival rates for advanced gastric cancer patients with P1 (n = 43), P2 (n = 56), and P3 (n = 36) metastasis were 16.3%, 0%, and 0%, respectively. The prognosis of P1 gastric cancer patients was significantly better than that of either P2 (P = 0.0003) or P3 patients (P < 0.0001). A multivariate analysis identified gross appearance and curability as independent prognostic indicators in P1 gastric cancer patients. In fact, the prognosis was good for patients in whom an R0/1 resection had been performed and with tumors having a gross appearance of other than type 4, with a 40% 5-year survival rate and a 29-month median survival time. [Conclusion] Our data indicated a good prognosis for P1 patients in whom an R0/1 resection could be performed and with tumors having a gross appearance of other than type 4. Therefore, radical surgery and adequate adjuvant chemotherapy should be performed in these patients.