First-line cetuximab plus capecitabine in elderly patients with advanced colorectal cancer: clinical outcome and subgroup analysis according to KRAS status from a Spanish TTD Group Study

Single-agent cetuximab is safe and active in elderly patients with advanced colorectal cancer (CRC). A cetuximab–capecitabine combination has not previously been tested in elderly patients with advanced CRC.

Material and Methods.

Sixty-six patients with advanced CRC were treated with cetuximab as a 400 mg/m² i.v. infusion followed by 250 mg/m² i.v. weekly plus capecitabine at a dose of 1,250 mg/m² every 12 hours. After the inclusion of 27 patients, the protocol was amended for safety reasons, reducing the dose of capecitabine to 1,000 mg/m² every 12 hours. Thirty-nine additional patients were treated with the reduced dose of capecitabine.

Results.

The overall response rate was 31.8%. KRAS status was determined in 58 patients (88%). Fourteen of 29 patients with wild-type KRAS tumors responded (48.3%; 95% confidence interval [CI], 29.4%–67.5%), compared with six of 29 patients with mutant KRAS tumors (20.7%; 95% CI, 8.0%–39.7%). The median progression-free survival (PFS) interval was 7.1 months. The median PFS interval for patients whose tumors were wild-type KRAS was significantly longer than for those with mutant KRAS tumors (8.4 months versus 6.0 months; p = .024). The high incidence of severe paronychia (29.6%) declined (7.7%) after capecitabine dose adjustment.

Conclusions.

Cetuximab plus capecitabine at a dose of 1,000 mg/m² every 12 hours may be an alternative to more aggressive regimens in elderly patients with advanced wild-type KRAS CRC.