Survival outcome of Borrmann type IV gastric cancer potentially improved by multimodality treatment

Type IV macroscopic gastric cancer has the poorest prognosis of all gastric cancer types. Although progress of multidisciplinary treatments is outstanding, the current survival outcome of such therapies is obscure.

Among 5,172 patients with gastric cancer between 1971 and 2013, 287 cases of type IV were identified (5%). We divided time period into early (1971-2004) and late periods (2005-2013), and compared their prognosis. Multivariate Cox proportional hazards model was applied to the univariate prognostic factors, and identified independent prognostic factors and long-term survivors.

Five-year overall survival (OS) was 13% and 31% in the early and late periods, respectively (p=0.0010). Univariate prognostic factors were age, pathological tumor depth of invasion (pT), pathological lymph node metastasis (pN), peritoneal dissemination (P), intra-peritoneal cytology test (CY), and margin status. Multivariate analysis determined independent prognostic factors to be treatment period (p=0.0001), pT (p=0.0024) and P (p=0.035). Survival outcomes were stratified by combination of pT and P in both periods, where OS was improved in the late period. Long-term survivors often underwent long-term postoperative chemotherapy with S-1.

Long-term postoperative S-1 chemotherapy may improve survival outcome of patients with type IV gastric cancer, and their prognosis is predicted by pT and P status.