BACKGROUND We aimed to determine the role of palliative resection in metastatic colorectal cancer (mCRC) and ascertain which patient populations would benefit most from this treatment.

METHODS A total of 1015 patients diagnosed with mCRC at Seoul National University Hospital between 2000 and 2009 were retrospectively studied.

RESULTS Of the 1015 patients, 168 patients with only liver and/or lung metastasis received curative resection. The remaining 847 patients were treated with palliative chemotherapy and/or palliative resection combined with best supportive care. Palliative resection was performed in 527 (62.2%) cases (complete resection with negative margin (R0) in 93, R1/2 in 434). Resected patients had a more prolonged median overall survival (OS) than unresected patients (21.3 vs 14.1 months; P<0.001). In multivariate analysis, R0 resection was found to be associated with a superior OS compared with R1/2 resection (51.3 vs 19.1 months; P<0.001) and no resection (51.3 vs 14.1 months; P<0.001). When we performed propensity score matching, palliative resection was found to be related to prolonged OS (hazard ratio=0.72, 95% confidence interval=0.59-0.89; P=0.003).

CONCLUSION Palliative resection without residual disease and chemotherapy confers a longer-term survival outcome than palliative chemotherapy alone in mCRC patient subset.