Prospective observational study of bevacizumab combined with paclitaxel as first- or second-line chemotherapy for locally advanced or metastatic breast cancer: the JBCRG-C05 (B-SHARE) study

Purpose: To investigate the effectiveness and safety of bevacizumab-paclitaxel combination therapy as first- or second-line chemotherapy for HER2-negative locally advanced or metastatic breast cancer in daily clinical practice.

Methods: In this prospective multicenter observational study, bevacizumab-paclitaxel was administered at the discretion of attending physicians. Cohorts A and B had hormone receptor-positive and triple-negative breast cancer (TNBC), respectively. Primary endpoint was overall survival (OS). Multivariate analyses were conducted to identify prognostic factors.

Results: Between November 2012 and October 2014, 767 patients were enrolled from 155 institutions across Japan. Effectiveness was analyzed in 754 eligible patients (cohort A, 539; cohort B, 215) and safety in 750 treated patients (median observation period, 19.7 months). Median OS (95% CI) was 21.7 (19.8-23.6) months in eligible patients; 25.2 (22.4-27.4) months and 13.2 (11.3-16.6) months in cohorts A and B, respectively; and 24.4 (21.9-27.2) months and 17.6 (15.2-20.0) months in patients receiving first- and second-line therapy, respectively. Factors affecting OS (hazard ratio 95% CI) were TNBC (1.75, 1.44-2.14), second-line therapy (1.35, 1.13-1.63), ECOG performance status ≥ 1 (1.28, 1.04-1.57), taxane-based chemotherapy (0.65, 0.49-0.86), cancer-related symptoms (0.56, 0.46-0.68), and visceral metastasis (0.52, 0.40-0.66). Incidences of grade ≥ 3 AEs hypertension, neutropenia, peripheral neuropathy, proteinuria, and bleeding were 35.7%, 27.2%, 7.2%, 3.7%, and 0.3%, respectively.

Conclusions: In Japanese clinical practice, combined bevacizumab-paclitaxel was as effective as in previous studies. Factors that independently predicted poor prognosis in the present study are consistent with those identified previously.

Trial registration: Trial no. UMIN000009086.

Keywords: Bevacizumab; First line; Locally advanced breast cancer; Metastatic breast cancer; Overall survival; Paclitaxel; Second line.