The prognostic implications of primary colorectal tumor location on recurrence and overall survival in patients undergoing resection for colorectal liver metastasis

Background and Objectives: The prognostic impact of primary colorectal cancer (CRC) location following resection of colorectal liver metastasis (CRLM) remains largely unknown. We sought to characterize the prognostic implications of primary tumor location among patients who underwent curative-intent hepatectomy for CRLM. Methods: Tumors of the cecum, ascending, and transverse colon were defined as right-sided; tumors of the sigmoid flexure, descending, and sigmoid colon were defined as left-sided. Clinicopathologic and long-term survival data were collected and assessed using univariable and multivariable analyses. Results: About 475 patients who underwent CRLM resection at a single institution were included; most patients had left-sided tumors (n = 284). Median and 5-year RFS was 20.2 months and 28.0%, respectively. Patients who had a left-sided primary tumor had a shorter RFS compared with patients who had a right-sided tumor (P = 0.01). Although site of and time to recurrence did not differ between the two groups (P > 0.05), patients with right-sided primary tumors were more likely to recur with advanced disease (i.e., ≥4 recurrent lesions) (P < 0.01). In turn, patients with right-sided tumors had both worse OS (P = 0.03) and worse survival after recurrence (P = 0.01). Conclusion: While patients with right-sided tumors experienced longer RFS, when these patients did recur following CRLM resection, disease extent was more advanced. In turn, OS following recurrence was shorter among patients with right-sided CRC. J. Surg. Oncol. 2016;114:803–809.