Is the negative prognostic impact of signet ring cell histology maintained in early gastric adenocarcinoma?

Background. Although the signet ring cell histologic subtype (SRC) is an independent predictor of poor prognosis in advanced gastric adenocarcinomas (GA), its prognostic value in early GA remains highly controversial. The aim of the study was to evaluate the prognostic impact of SRC in mucosal and submucosal GAs. Methods. Based on a multicenter cohort of 3,010 patients operated on for GA between January 1997 and January 2010, patients with pTis or pT1 tumors were extracted and analyzed comparatively between the SRC and non-SRC groups. The primary objective was to compare the 5-year survival rate between groups. Results. Among 421 patients with a pTis or pT1 tumor, 104 (25%) were SRC and 317 (75%) were non-SRC. Demographic variables were comparable between groups, except median age, which was less in the SRC group (59.6 vs 68.8 years; P < .001). Submucosal involvement was more frequent in the SRC group (94% vs 85%; P = .043), whereas lymph node involvement and number of invaded nodes were comparable between the 2 groups. When comparing SRC and non-SRC, recurrence rates (6% vs 9%; P = .223) and sites of recurrence were similar. The 5-year overall survival benefit in SRC patients (85% vs 76%, respectively; P = .035), was not evident when considering exclusively disease-specific survival or in multivariable analysis. Conclusion. Contrary to more advanced GA, SRC morphologic subtype is not a negative prognostic factor in early GA. Better survival identified in some reports may be related to the younger age in SRC patients.