First-line single-agent cetuximab in elderly patients with metastatic colorectal cancer. A phase II clinical and molecular study of the Spanish group for digestive tumor therapy (TTD)

Purpose: To evaluate the efficacy and safety of first-line single-agent cetuximab in fit elderly patients with metastatic colorectal cancer, as well as potential molecular predictive factors for efficacy. Patients and methods: Patients aged 70 or older with metastatic CRC without criteria for frailty and no prior treatment for advanced disease were treated with single-agent cetuximab 400mg/m² followed by weekly 250mg/m² until disease progression or unacceptable toxicity. Results: Forty-one patients were included. Two patients achieved a complete response and 4 patients had a partial response for an overall response rate of 14.6%. Fifteen patients (36.6%) remained stable. Median time to progression was 2.9 months and median overall survival 11.1 months despite two-third of patients received chemotherapy at progression. Forty-five percent of EGFR gene copy number positive patients by FISH were progression-free at 12 weeks, in contrast with 12% of FISH negative patients (p= 0.04). Grade 3 skin toxicity was reported in 5 patients (12.2%). Hypersensitivity infusion reactions were not reported and there were no toxic deaths. Conclusion: Cetuximab is a safe monoclonal antibody with moderate activity in first-line metastatic colorectal cancer, but the present study does not support the use of cetuximab as single-agent in first-line fit elderly patients with metastatic CRC.