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

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. 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. 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. 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 no. UMIN000009086.