Survival Following Synchronous Colon Cancer Resection

Background: Synchronous colon cancers, defined as two or more primary colon cancer detected simultaneously at the time of initial diagnosis, account for up to 5% of all colon cancer diagnoses. Management principles and outcomes remain largely undefined. Methods: Aretrospective institutional review of patients undergoing curative intent resection for colon adenocarcinoma (Stages I-III) from 1995 to 2007 was performed. Hereditary causes or inflammatory bowel disease were excluded. Matching was performed and Kaplan-Meier analysis was used to compare overall survival. Results: Of 2,387 patients, 100 (4.2%) had synchronous cancers. Patients with synchronous lesions tended to be older (median 77 vs. 72 years, P < 0.001) with more advanced tumors (41.0% vs. 31.4% Stage III, P = 0.04). After matching, there were no differences in demographics or tumor factors (all P > 0.05). Compared to solitary, synchronous cancers demonstrated an inferior 10-year overall survival (53.9% vs. 36.5%, P = 0.009). Subset analysis of patients with synchronous cancers showed no difference in overall survival between those with extended versus segmental resections at 120-months (P = 0.07). Conclusion: Synchronous colon cancer is associated with decreased overall survival compared to patients with solitary tumors. Extended resection does not confer a survival benefit in these patients. Further research is needed to determine how to mitigate the poor outcomes. (C) 2016 Wiley Periodicals, Inc.