Palliative resection of the primary tumour improves survival in incurable metastatic colorectal cancer

Background: Studies show conflicting results on whether primary tumour resection (PTR) in metastatic colorectal cancer (mCRC) prolongs survival. The aim of this study was to analyse prognostic factors and the effects of PTR on overall survival (OS) in mCRC patients. Methods: In this population-based cohort study, factors associated with PTR and OS were assessed in 188 mCRC patients with mCRC treated with palliative chemotherapy between 2008 and 2019. The Chi-square test and Mann-Whitney U-test were used to assess factors associated with PTR. The log-rank test was used to compare Kaplan-Meier estimates for OS. Cox regression was used to identify factors predicting OS. Results: Patients undergoing PTR had significantly better performance status, fewer metastatic sites, lower CEA levels, and more often had left-sided CRC than patients not undergoing PTR. OS was longer in palliative mCRC patients undergoing PTR (P < 0.01) and PTR was an independent variable in the Cox regression analysis (P < 0.05). Median OS was 22.9 +/- 1.9 months for the PTR group and 14.5 +/- 1.5 months for the non-operated group. Poor performance status and liver metastases were significantly associated with poor prognosis. Conclusion: This study shows that PTR had a positive effect on OS and may be considered in patients suitable for surgery. PTR was offered to palliative mCRC patients with prognostic factors associated with better prognosis.