Signet Ring Cell Carcinoma of Resectable Metastatic Colorectal Cancer Has Rare Surgical Value

Background and Objectives: Signet ring cell carcinoma (SRCC) is a uniquely separated subgroup in metastatic colorectal cancer (mCRC). The aims are to investigate the value of resection in patients with resectable metastatic signet ring cell colorectal cancer. Methods: Patients with mCRC who underwent resection in Surveillance, Epidemiology, and End Results database during 1998-2010 were retrospectively analyzed. Kaplan-Meier and COX models were used to analyze the differences in the survival. Logistic regression models were used to evaluate the relationship between SRCC and other clinicopathological factors. Results: Among the 3,568 patients, 94 (2.63%) patients had SRCC. The median survival time of patients with SRCC and non-SRCC were 17 and 29 months, respectively (P < 0.001). Multivariate analysis indicated that SRCC was an independent prognostic factor for poor overall survival. Logistic regression model based on variables identified by univariate analysis indicated that younger age (<= 50 years old) (P = 0.005), female (P < 0.001), location in colon (P = 0.012), and N positive status (P = 0.003) were independent variables correlated with the SRCC subgroup. SRCC had a dramatically higher invalid surgical outcome rate than non-SRCC (P = 0.001). Conclusion: SRCC patients might benefit little from the resection of primary and metastatic lesions with a high rate of undergoing invalid operations. (C) 2016 Wiley Periodicals, Inc.