Stage-stratified prognosis of signet ring cell histology in patients undergoing curative resection for gastric adenocarcinoma.

ABSTRACT

BACKGROUND: The prognosis of signet ring cell (SRC) gastric adenocarcinoma is regarded as poor, although studies addressing outcomes in relation to non-SRC tumors are conflicting. Our objective was to compare the survival of SRC tumors with stage-matched intestinal-type tumors in a cohort of Western patients. METHODS: Review of a prospectively maintained database identified 569 patients undergoing curative resection (R0) from 1990 to 2009. Patients were divided into three histologic groups on the basis of the Lauren classification SRC (n = 210), intestinal well- or moderately differentiated (WMD, n = 242) disease, and intestinal poorly differentiated (PD, n = 117) disease. Patient demographics, clinicopathologic features, and postoperative outcomes were determined. Stage-stratified disease-specific mortality was calculated and multivariate analysis performed. RESULTS: When compared with WMD and PD tumors, SRC tumors were associated with younger age (63 years SRC vs. 71 years WMD and 72 years PD, p < 0.0001) and with female sex (58 % SRC vs. 40 % WMD and 40 % PD, p = 0.0003). Median follow-up was 115 months. Patients with stage Ia SRC lesions had a better 5-year disease-specific mortality compared with stage-matched intestinal-type tumors (0 % SRC vs. 8 % WMD and 24 % PD, p = 0.001). In contrast, SRC patients with stage III disease fared significantly worse (78 % SRC vs. 54 % WMD and 72 % PD, p = 0.001). On multivariate analysis, the risk of death from gastric cancer comparing all three groups was lowest for SRC in stage I and highest for SRC in stage III disease (stage III hazard ratio SRC 1 vs. 0.47 WMD and 0.85 PD). CONCLUSIONS: When compared with intestinal-type tumors, SRC tumors at early stages are not necessarily associated with poor outcomes.