Cetuximab in third-line therapy of patients with metastatic colorectal cancer: A single institution experience.

Objective: Cetuximab, an IgG1 chimeric monoclonal antibody (MAB) against epidermal growth factor receptor (EGFR) has activity against metastatic colorectal cancers (mCRC) that express EGFR. The purpose of this study was to demonstrate the efficacy and safety of cetuximab administered to patients with EGFR-positive mCRC.

Methods: 72 patients with wild-type KRAS mCRC were enrolled. All of them had previously been treated with a fluoropyrimidine, oxaliplatin and irinotecan-based chemotherapy. Patients received cetuximab as monotherapy or in combination with irinotecan-based chemotherapy. All patients were to be treated until the occurrence of disease progression or unacceptable toxicity.

Results: All patients were evaluated for progression free survival (PFS), overall survival (OS) and safety. The median PFS was 4.77 months (95% CI: 4.08-5.45), with an actuarial 47.22% without progression at 3 months and 16.67% at 6 months. The median OS was 11.35 months (95% CI: 9.64-13.06), with 79.17% of the patients being alive at 6 months and 30.56% at 12 months. PFS was significantly higher in patients with skin toxicity as compared to those without skin toxicity (5.31 vs 2.61 months, p<0.001) and with smaller number of metastatic organs vs greater number of metastatic organs (p=0.05). OS was significantly higher in patients with good performance status (p=0.004), with skin toxicity (p=0.013) and with smaller number of metastatic organs (p<0.001). Superior survival rates with higher grades of skin toxicity were noticed. As for patient characteristics, there were no significant differences in age, gender, and primary site localization.

Conclusions: Cetuximab improved PFS, OS and preserved the quality of life in patients with mCRC whose previous treatments had failed.