Oncologic outcomes following metastasectomy in colorectal cancer patients developing distant metastases after initial treatment

PURPOSE: We performed a comparative analysis of the clinicopathologic features and oncologic outcomes of colorectal cancer patients with metachronous versus synchronous metastasis, according to the prognostic factors. METHODS: Ninety-three patients who underwent curative resection for distant metastatic colorectal cancer were included in the study between December 2001 and December 2011. We assessed recurrence-free survival and overall survival in patients with distant metastasis who underwent curative surgery. RESULTS: The most common site of distant metastasis was lung alone (n = 19, 51.4%) in patients with metachronous metastasis, while liver alone was most common in those with synchronous metastasis (n = 40, 71.4%). Overall survival rate was significantly different between patients with synchronous metastasis and metachronous metastasis (34.0% vs. 53.7%; P = 0.013). Incomplete resection of the metastatic lesion was significantly related to poor overall survival in both, patients with synchronous metastasis, and metachronous metastasis. CONCLUSION: Our study indicates that patients developing distant metastasis after initial treatment show a different metastatic pattern and better oncologic outcomes, as compared to those presenting with distant metastasis. Resection with tumor free margins significantly improves survival in patients with metachronous as well as synchronous metastasis.