Primary tumor resection in patients presenting with metastatic colorectal cancer: analysis of a provincial population-based cohort

PURPOSE

We conducted a Canadian population-based study to assess surgical practice patterns and outcomes among patients with metastatic colorectal cancer (mCRC) at diagnosis.

METHODS

We reviewed a provincial cancer registry for 2 years. Four hundred eleven patients presenting with mCRC were stratified by primary tumor resection status. Baseline characteristics, treatment modalities, and outcomes were assessed.

RESULTS

Seventy percent of patients underwent resection. Resected patients were less likely to have rectal primaries (16% vs. 42%, P < or = 0.001) and had more obstructive symptoms (47% vs. 31%, P < or = 0.001) or bleeding (26% vs. 6%, P < or = 0.001). They experienced fewer tumor-related complications (4% vs. 22%, P < or = 0.001). Use of first-line chemotherapy was similar (61% vs. 58%, P = 0.54), but the resection cohort was more likely to receive doublet chemotherapy (57% vs. 36%, P < or = 0.01) and metastatectomy (10% vs. 0%, P < or = 0.0001). Among patients with rectal tumors, radiation use was comparable (63% vs. 58%, P = 0.68). Median survival was longer in the resection group (14 vs. 6 months, P < or = 0.001).

CONCLUSIONS

Most patients presenting with mCRC underwent primary resection. Colonic tumors, obstruction, and bleeding were associated with resection. In situ primaries conferred more complications, despite similar use of radiation in cases of rectal cancer. Unresected patients were less likely to receive doublet chemotherapy or metastatectomy, and had inferior survival.