Different clinicopathologic features and prognostic significance of signet ring cell histology in early and locally advanced gastric cancer patients.

BACKGROUND: Although many studies have evaluated the prognostic significance of signet ring cell (SRC) histology for gastric cancer (GC) patients, the results were conflicting. The objective of this study was to compare clinicopathologic characteristics between SRC type and other types, and evaluate its impact on survival outcome. METHODS: We retrospectively reviewed clinicopathologic and survival data of 1891 patients who underwent curative resection for GC. All patients were divided into differentiated, undifferentiated and SRC type according to the histological classification. The prognostic differences between different types were compared and clinicopathologic factors were analyzed. RESULTS: SRC histology type had a poorer disease-free survival (DFS) than differentiated type (5-year DFS, 37.7% vs 52.2%, P<0.001), but there was no prognostic difference between SRC type and undifferentiated type (37.7% vs 41.9%, P>0.05). For early GC patients, SRC type was more frequent in younger, female patients and T1a stage tumors; the 5-year DFS of SRC type was similar to that of any other histology type (P>0.05). SRC type showed more aggressive biological features, including extensive stomach involvement, large tumor size, advanced pTstage and pN stage, than other types for locally advanced GC patients; poorer DFS was observed in SRC type compared with differentiated type. Multivariate analysis indicated that SRC type (HR:1.71, 95%CI:1.10-1.68, P<0.01) and undifferentiated type (HR:1.21, 95%CI:1.04-1.40, P<0.05) were independently associated with poor DFS in locally advanced GC patients. CONCLUSION: There was a significant difference between early and locally advanced GC patients with regard to clinicopathologic features and prognostic significance of SRC histology. SRC type was an independent prognostic factor for locally advanced GC patients, but not for early GC patients.