Chemotherapy with bevacizumab for metastatic colorectal cancer: a retrospective review of 181 Japanese patients.

Background: There has so far been little information on the clinical effect of bevacizumab against colorectal cancer in Japan. Hence, this study was conducted to retrospectively evaluate the safety and efficacy of bevacizumab in clinical practice.

Methods: A total of 181 patients with metastatic colorectal cancer (mCRC) received bevacizumab in combination with chemotherapy at 18 hospitals in Kumamoto prefecture, Japan. We surveyed the medical records of all patients regarding the patient characteristics, objective tumor responses, and adverse events. We analyzed their overall survival and the survival benefit when continuing the administration of bevacizumab beyond disease progression (progressive disease; PD) in patients who received bevacizumab-containing 1st line therapy.

Results: The response rate (RR) in all lines of therapy was 42 %. The 1st line patients showed significantly better survival in comparison to the patients who received further lines of treatment (P = 0.005). There were no significant differences in survival between the group with post-PD treatment with bevacizumab and the group with post-PD treatment without bevacizumab (P = 0.13). The most common grade 3 or greater adverse event associated with bevacizumab was hypertension (12.2 %). Especially, a high incidence of gastrointestinal (GI) perforation was shown in this study (4.4 %) and most of the patients with GI perforation had some risk factors for this complication.

Conclusion: Although the survival benefit of bevacizumab in Japanese patients with mCRC was similar to that observed in previous clinical trials, this study showed a high incidence of GI perforation in comparison to previous studies. Therefore, the careful selection of patients with few risk factors for this complication is likely to lead to a greater benefit from bevacizumab treatment.