Synchronous metastatic colon cancer and the importance of primary tumor laterality-A National Cancer Database analysis of right-versus left-sided colon cancer

Background: The role of laterality for patients with synchronous metastatic colon cancer (SMCC) is not well-defined. Methods: Using the National Cancer Database (2010-2015), we compared patients with metastatic right(RCC) versus left-sided colon cancer (LCC). We performed Kaplan-Meier analysis to compare overall survival (OS) for each metastatic site and utilized adjusted Cox proportional hazard analysis to identify predictors of OS. Results: Patients with RCCs were more likely to be older, female, and have more comorbidities. LCCs were more likely to metastasize to liver and lung, whereas RCCs were more likely to metastasize to peritoneum and brain. There was equal likelihood to metastasize to bone. OS was significantly longer for LCCs for all metastatic sites. After controlling for multiple variables, RCC (HR 1.426, p < 0.001) remained an independent predictor of worse OS compared to LCC. Conclusions: Laterality of the primary tumor plays an important role in outcomes for patients with SMCC. (c) 2019 Elsevier Inc. All rights reserved.