Treatment outcomes in patients with signet ring cell carcinoma of the colorectum

Background: The aim of this study was to evaluate the clinicopathologic features and prognosis of signet ring cell (SRC) carcinoma and compare them with those of mucinous and poorly differentiated adenocarcinomas of the colorectum. Methods: The clinicopathologic data of 35 patients with primary SRC carcinoma were reviewed and compared with the data from 294 patients with mucinous and 252 patients with poorly differentiated adenocarcinoma. Results: Eighty percent of the SRC patients presented with more advanced disease (stages III and IV), whereas 55.1% and 64.7% of the patients in the mucinous and poorly differentiated groups had advanced disease at diagnosis, respectively (80% vs 55.1%, P = .04 and 80.0% vs 64.7%, P = .437). Median survival time for patients with SRC was 18.4 months (95% confidence interval 10.4 to 19.6). Three- and 5-year survival rates in the SRC group were 33.7% and 25.3%, respectively. The overall survival rate of patients with SRC was significantly poorer than that of patients with mucinous or poorly differentiated adenocarcinoma (P < .001). Conclusions: SRC of the colorectum is characterized by advanced stage at diagnosis with lower rates of curative resection. It tends to affect younger patients with more propensity for lymphovascular invasion.