Clinicopathological differences in signet ring cell adenocarcinoma between early and advanced gastric cancer

Background: Signet ring cell adenocarcinoma is a histological classification based on the WHO classification. The presence of this specific histological type is associated with a worse pathological appearance. The prognosis of signet ring cell adenocarcinoma in gastric cancer patients after curative surgery is still under debate. Methods: From January 1988 to December 2012, a total of 2971 patients, including 819 early and 2152 advanced gastric cancer patients underwent curative resection for gastric cancer. Among them, there were 185 cases of signet ring cell adenocarcinoma in early gastric cancer patients, while there were 570 cases in advanced gastric cancer patients. Results: The overall incidence of signet ring cell adenocarcinoma was 25.4%. Our results showed that the 5-year overall survival rates of early gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 90.7 and 83.2%, respectively (P = 0.001). The 5-year disease-free survival rates of early gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 87.4 and 81.6%, respectively (P = 0.003). The 5-year overall survival rates of advanced gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 32.1 and 37.9%, respectively (P = 0.041). The 5-year disease-free survival rates of advanced gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 28.6 and 35.2%, respectively (P = 0.037). Signet ring cell adenocarcinoma was an independent predictor for overall survival in advanced gastric cancer (P = 0.017). Conclusion: The clinical features and prognosis of signet ring cell adenocarcinoma are different between early and advanced gastric cancer. Signet ring cell adenocarcinoma is a poor prognostic factor in advanced gastric cancer after curative resection.