Primary Tumor Location and Survival Among Metastatic Colorectal Cancer Patients treated with systemic chemotherapy, and biologic therapies: Retrospective Analysis (2013-2016)

Abstract

Purpose: In a sample of Middle Eastern population, we sought to evaluate whether survival outcomes for mCRC patients treated with systemic chemotherapy (SC) and, with and without biologic therapies (bevacizumab and cetuximab) are different between left and right-sided tumors. Methods: Ministry of National Guard- Health Affairs (MNG-HA) Cancer registry data was utilized to identify patients diagnosed with CRC between 2013 and 2016. Kaplan-Meier method and porosity score adjusted Cox proportional hazard models were used to assess survival for right and left-sided mCRC with and with BT. Results: A total of 196 mCRC patients with mean age of 64 years old, 57.65% male diagnosed from January 1, 2013, through December 31, 2016. The overall median survival for left-sided was significantly higher than right-sided mCRC tumors (P 0.03). mCRC patients treated with SC+BT were associated with decreased mortality only among patients with left-sided mCRC compared to right-sided mCRC (HR, 0.21; 95% CI, 0.05-0.92; P .03). mCRC with no primary-tumor resection and CS+TB left-sided mCRC was significantly associated with decreased mortality compared to right-sided mCRC (HR, 0.15; 95% CI, 0.03-0.72; P .02).Conclusions: In a sample of Middle Eastern population, a significant decrease in mortality for left-sided mCRC treated with SC plus BT compared with right-sided mCRC was observed. mCRC patients with unresectable metastases demonstrated survival benefit from left-sided SC plus BT treatment. Randomized controlled trials are needed to determine the optimal treatment for mCRC patients.