Evaluating the effectiveness and safety of different bevacizumab schedules in combination with chemotherapy for the treatment of patients with metastatic colorectal cancer.

This study investigated the effectiveness and safety of bevacizumab (Avastin) administered either on the same day or a few days before chemotherapy for the treatment of patients with metastatic colorectal cancer (mCRC). The data showed that bevacizumab administered 4 days before chemotherapy significantly improved overall survival with fewer side effects than on the same day.

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. Some patients do not report symptoms with the initial tumor. These patients are often only diagnosed when the cancer has spread to other areas (metastatic CRC). The standard treatment for these patients is chemotherapy combined with targeted therapy. 

Bevacizumab is a type of targeted therapy. It works by stopping tumors from forming new blood vessels and spreading. Studies have shown that bevacizumab improves the outcomes of patients with mCRC when added to chemotherapy. However, it is not known the timing of bevacizumab on the same day as or before chemotherapy would impact treatment effectiveness and safety in patients with mCRC.

This study involved 230 patients with mCRC. Patients were randomly assigned into 2 groups. Group 1 included 115 patients who received bevacizumab the same day as chemotherapy. Group 2 included 115 patients who received bevacizumab 4 days before chemotherapy. The average follow-up time was 68.3 months.

Overall, 57.4% of patients in group 1 and 56.5% of patients in group 2 responded to treatment. The average overall survival was significantly longer for group 2 (29.8 months) compared to group 1 (24.1 months). Bevacizumab given 4 days before chemotherapy was associated with a 27% higher chance of survival compared to when it was given on the same day. 

Patients in group 2 had significantly reduced rates of diarrhea (5.3%) and nausea (1.8%) compared to patients in group 1 (16.5% and 7%). Patients in group 2 also had improved physical conditioning and lower rates of constipation compared to patients in group 1.

This study concluded that bevacizumab administered 4 days before chemotherapy significantly improved overall survival and was better tolerated for the treatment of patients with mCRC.

This study was carried out only in Italian institutions and may not translate to different populations. The response criteria used to evaluate treatment response were not considered the most accurate. This may have affected the comparison of response to treatment.