[Clinical impact of addition of bevacizumab to the first-line chemotherapy regimen in the treatment of patients with metastatic colorectal cancer].

Abstract Combination regimens containing bevacizumab(BV)are regarded as one of the standard first-line chemotherapy (1stCTx) regimens in the treatment of metastatic colorectal cancer (mCRC). However, some patients cannot be treated with BV because of the short interval from the palliative operation or other reasons. We present a study of some patients who were treated with add-on BV in the middle of the 1stCTx before disease progression(referred to as "midway BV" regimen hereafter), and here, we report the efficacy of the midway BV regimen as observed in our patients. We retrospectively analyzed the data of 74 mCRC patients, who were undergoing 1stCTx treatment at our hospital from January 2010 to September 2012. We divided the patients into 3 groups, depending on when BV was introduced in their regimen: 40, 25, and 9 patients were respectively included in the "no-BV" group (patients who were treated without BV in the 1stCTx), BV group(patients treated with BV from the 1st cycle in the 1stCTx), and the midway-BV group (patients who were initially treated without BV and then received add-on BV). The response rates of patients in the no-BV, BV, and midway-BV groups were 27.5%, 44.0%, and 55.6%, respectively. The median progression-free survival (PFS) and median survival time of patients in the no-BV, BV, and midway-BV groups were, respectively, 9.7 months, 9.3 months, and 12.8 months, and 20.3 months, 22.2 months, and N. R. Although few cases were analyzed and there might be many confounding factors, our study suggests that midway BV is potentially useful for patients with metastatic colorectal cancer who are not initially treated with BV in the first cycle of the 1stCTx regimen.