The characteristics and prognostic value of signet ring cell histology in gastric cancer: A retrospective cohort study of 2199 consecutive patients.

Although signet ring cell cancer (SRCC) has long been regarded as an adverse prognostic factor of gastric cancer, the findings of existing studies on this issue are inconsistent. We conducted a retrospective cohort study of 2199 consecutive patients with gastric cancer treated in a tertiary cancer hospital in Beijing, China, 1994 to 2013. The characteristics of SRCC and non-SRCC were compared. The prognostic effects of SRCC and other important clinicopathological factors on overall survival were evaluated by both univariate and multivariate Cox regression analyses and expressed as hazard ratio (HR) with 95% confidence interval (CI). SRCC accounted for 16.1% of gastric cancer, increasing from 6% to 20% over the last 2 decades, and was associated with younger age, female sex, poor differentiation, diffuse type, and distal location. SRCC (HR: 1.387, 95% CI: 1.177-1.634), stage (HR: 1.752, 95% CI: 1.458-2.106), surgery (palliative resection: HR: 0.712, 95% CI: 0.590-0.859; curative resection: HR: 0.490, 95% CI: 0.380-0.633), performance status (HR: 1.849, 95% CI: 1.553-2.201), and age (HR: 1.070, 95% CI: 1.001-1.143) were independent prognostic factors for gastric cancer, whereas time period of diagnosis, sex, and tumor location were not statistically significantly associated with overall survival. Subgroup analyses showed that the prognostic value of SRCC did not vary much with age, sex, performance status, stage, and surgery and chemotherapy status. As compared with non-SRCC, SRCC accounted for increasingly more of gastric cancer and was associated with younger age, female sex, poor differentiation, diffuse type, and distal location. It was an independent prognostic factor associated with worse survival in gastric cancer.