Does primary tumor resection contribute to overall survival in unresectable synchronous metastatic colorectal cancer

Background: Primary tumor resection (PTR) in metastatic colorectal cancer (mCRC) has not been suggested by guidelines, since new systemic chemotherapy options have improved overall survival. However, the effect of PTR is still controversial in mCRC. In this study, we aimed to evaluate the effect of PTR on survival in unresectable mCRC. Materials and Methods: Two hundred and fifty-two patients with unresectable mCRC were screened retrospectively between January 2007 and December 2017 and a total of 147 patients who met inclusion criteria were included. The patients with emergency or elective PTR and the patients without surgery were compared for baseline features and overall survival. Results: The median follow-up time was 15.6 months (range; 1.2-78.9) in whole patients. There were 91 patients in nonsurgical (NS) group and 56 patients in PTR group. The median overall survival was significantly longer in PTR group compared NS group (21.8 vs. 17.0 months, P = 0.01), but it was not associated to better overall survival in multivariate Cox analysis (hazard ratio: 0.65, 95% confidence interval: 0.41-1.02, P = 0.06). There was no significant difference in overall survival between emergency and elective surgery subgroups (22.9 vs. 16.1 months, respectively, P = 0.9). Conclusion: PTR did not offer an overall survival benefit in this study. Although it is debated, we think that it is better to start treatment with chemotherapy and biological agent combinations in patients with asymptomatic mCRC. Thus, the patients can be protected from the morbidity and mortality of the surgery.