Search

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.

Akt is a serine/threonine kinase that has been demonstrated to play an important role in survival when cells are exposed to different apoptotic stimuli. Recent studies show that aberrant activation of Akt in breast carcinoma is associated with a poor prognosis and resistance to endocrine therapy and chemotherapy. The Akt signaling pathway is currently attracting considerable attention as a new target for effective therapeutic strategies. We investigated the incidence of Akt activation in 252 primary breast carcinomas and relationships among the activation of Akt, HER2 overexpression, hormone receptor expression, and alteration of the PTEN gene. Eighty-four cases (33.3%) were positive for pAkt expression. pAkt was significantly associated with HER2 overexpression (p<0.0001) and LOH at the PTEN gene locus (p<0.01). There was an inverse correlation between pAkt and PR (p<0.05). We also retrospectively examined the relationship between Akt activation and the efficacy of endocrine therapy for metastatic breast cancer. Of these 36 metastatic breast cancer cases, 12 cases (33.4%) were considered to show positive pAkt expression. In the pAkt-positive patients, endocrine therapy demonstrated worse efficacy than in pAkt-negative patients (p<0.01). In addition, the clinical benefit was the smallest in the patients positive both for HER2 and pAkt (p<0.01). The clinical benefit rate of estrogen deprivation therapy with AI or LH-RH agonist was significantly lower in the pAkt-positive patients than that in the pAkt-negative ones (p<0.05), and there was a tendency for the clinical benefit of SERM to be smaller in the pAkt-positive patients (p=0.09). These findings therefore suggest that Akt activation induces endocrine resistance in metastatic breast cancer, irrespective of the kind of endocrine agents that were administered. Our findings indicate that the activation of Akt in the downstream pathway of HER2 plays an important role in resistance to endocrine therapy for breast cancer. Our findings suggest that pAkt may be a useful predictor of resistance to endocrine therapy for breast cancer, while also suggesting that the inhibition of Akt may increase the efficacy of endocrine therapy.