Comparative analysis of the effectiveness of second-line bevacizumab plus chemotherapy in second-line therapy in metastatic colorectal cancer.

Abstract

619 Background: Advances in molecular biology and a wide introduction to the practice of targeted therapies have improved outcomes and significantly affect the overall survival of patients. To investigate the efficacy and safety of bevacizumab (BEV) beyond first progression combined with chemotherapy (CT) in patients with metastatic colorectal cancer. Methods: 68 patients with mCRC who received chemotherapy treatment at the Department of the Kazakh Research Institute of Oncology and Radiology. Selecting second-line chemotherapy based on oxaliplatin or irinotecan depended of an earlier first-line therapy (FOLFOX, FOLFIRI). The survival rate was calculated by Kaplan-Meier, comparison of survival curves was performed by log-rank. Results: The study included 68 patients, who were randomized from February 2009 to November 2011(to 33 [48.5%] BEV + CT and 35 [51.5%] to CT alone). Analysis of the immediate results of treatment showed that in neither case was not achieved complete response of the tumor. Partial regression in group 1 – 11 (33.3 ± 8.2)%, and group 2 - in 9 (25.7 ± 7.3)%. Stabilization is achieved in 20 (60.6 ± 8.5)% and 23 (6.7 ± 8.0)% of cases, respectively. The progression of the disease was observed in the group 1 in 2 (6.1 ± 4.1)% and 3 (8.6 ± 4.7)% of cases. Median progression-free survival (PFS) and overall survival (OS) was 11.5 months (7-16) and 12.2 months in group 1, and 9.7 months (6-13.2) (PFS), 9.1 months(OS) in group 2, respectively. The adverse event profile was consistent with previously reported data for BEV + CT. BEV-related significant adverse events included bleeding grade 3-4 (1.5 %) and venous thrombosis (2.3 %). Conclusions: Our findings demonstrate that BEV + CT continued beyond progression significantly prolong OS and PFS in second-line therapy mCRC.