Cetuximab combined with irinotecan improves the outcomes of patients with advanced colorectal cancer

This study investigated the effectiveness of irinotecan (Camptosar) with and without cetuximab (Erbitux) in the treatment of metastatic (spread to other parts of the body) colorectal cancer (mCRC). Researchers suggested that combined treatment improves the outcomes of these patients.

Colorectal cancer (CRC) is one of the most common cancers worldwide. In advanced cases treatment with chemotherapy such as irinotecan is only of limited effectiveness. The addition of other agents to the treatment improves the tumor response and the treatment outcomes. Some cancers have on their surface a protein called epidermal growth factor receptor (EGFR) that promotes cell growth. Targeted therapies that block EGFR such as cetuximab help in stopping cancer cells to spread.

Prior studies suggested that irinotecan plus cetuximab were associated with improved outcomes in patients with mCRC. However, the RAS mutation (permanent change in the gene) status was not considered. RAS mutation has been described as a predictor of the effectiveness of cetuximab treatment. This mutation makes cancer more aggressive which challenges the treatment. Therefore, the effectiveness of cetuximab plus irinotecan in patients with mCRC without RAS mutation is still not clear. 

This study included 446 patients with RAS-negative mCRC. These participants were assigned to receive cetuximab plus irinotecan (group 1; 229) or irinotecan alone (group 2; 217). Overall survival (OS; time from treatment to death by any cause), progression-free survival (PFS; time from treatment to disease progression), and tumor response rate were evaluated.

Patients from group 1 had a PFS of 5.4 months compared to 2.6 months in group 2. The tumor response rate was 29.4% in group 1 and 5% in group 2. Quality of life including mental status, physical functioning, fatigue and nausea, pain and appetite, improved in patients from group 1. The average OS was similar between groups 1 (12.3 months) and 2 (12 months).

Serious side effects were observed in 29.3% of patients from group 1 and 21.1% in group 2. The most common serious side effects in both groups were low white blood cell count with fever and diarrhea. In group 2, 47.1% of patients received further therapy with cetuximab.

This study concluded that the cetuximab plus irinotecan combination improves the outcomes of patients with RAS-negative mCRC.

This study was based on information from medical records. Data may have been missing.