Primary Tumor Resection Does Not Improve Survival in Metastatic Colon Cancer

Initial surgery for patients with metastatic colon cancer is clearly warranted when the primary tumor is bleeding or obstructing. However, for patients with asymptomatic tumors and metastases not amenable to curative resection, results from retrospective, phase 2, and phase 3 trials have varied, with some supporting and others questioning a survival benefit for upfront surgery. Investigators now report combined results from the SYNCHRONOUS and CCRe-IV randomized trials comparing upfront primary tumor resection (PTR) followed by chemotherapy to treatment with chemotherapy alone in patients with colon cancer and metastatic disease not curable with surgery.

Of the 393 patients, 95% had liver metastases. Primary tumors were left-sided in 53% of patients and right-sided in 45%. Also, 45% received an oxaliplatin-fluoropyrimidine doublet, 35% the addition of bevacizumab, and 18% an EGFR-targeting antibody. The median follow-up was 36.7 months. The primary endpoint of median overall survival was similar in the two groups (PTR, 16.7 months; no-PTR, 18.6 months). Chemotherapy was not given to 24% of patients in the PTR group and 6% of the no-PTR group. The no-PTR group had a significantly higher rate of serious adverse events (18%) than the PTR group (10%), due to more ileus or bowel obstructions (no-PTR group, 18 patients; PTR group, 2 patients).