Evaluating FOLFIRI plus cetuximab or bevacizumab in advanced colorectal cancer

This study compared the effectiveness of FOLFIRI (5-fluorouracil, folinic acid, and irinotecan) with either cetuximab (Erbitux) or bevacizumab (Avastin) in the treatment of advanced colorectal cancer (CRC). Researchers suggested that FOLFIRI with cetuximab resulted in improved response and longer survival for these patients.

Colorectal cancer is the third most common cancer worldwide. A significant number of patients present with advanced disease at diagnosis. Treatment with chemotherapy is of limited effectiveness in metastatic (spread to other parts of the body) cases. Adding other agents to the treatment might improve treatment outcomes.

Prior studies suggested that first-line FOLFIRI plus cetuximab improves survival in advanced CRC. This effectiveness is challenged by the presence of RAS mutation (a permanent change in the gene). RAS mutation was shown to have a negative impact on the effectiveness of this treatment.

The effectiveness of this CRC treatment in RAS-negative patients who progressed after three or more cycles of therapy is still not clear.

This study included information about 352 patients with RAS-negative advanced CRC. All participants previously received 3 or more cycles of therapy. Patients were assigned to receive FOLFIRI with either cetuximab (169; group 1) or bevacizumab (183; group 2). The main outcomes measured were tumor response rate, overall survival (OS), and progression-free survival (PFS). The effect of tumor location was also investigated.

The average OS (time from treatment to death by any cause) was 31 months in group 1 and 26 months in group 2. Patients from group 1 had a 24% improvement in the odds of a better OS when compared to group 2. The tumor response rate was 77% in group 1 and 65% in group 2. PFS (time from treatment to progression) was similar between both groups. The treatment effect observed in group 1 over group 2 was only observed in patients with left-sided tumors.

This study concluded that FOLFIRI plus cetuximab improves tumor response and survival in patients with advanced CRC who received 3 or more prior therapies.