0380: Cardiac tolerance of bevacizumab associated with trastuzumab and conventional treatment in patients with primary inflammatory HER2positive breast cancer

Abstract

Breast cancer is the most frequent female cancer. Treatment of HER2+ tumours evolved with immunotherapy, leading to improved survival. Cardiac toxicity associated to trastuzumab is frequent but reversible in 75% of cases. However, only little is know about the cardiotoxicity of new anti-VEGF antibodies associated to trastuzumab. In this study, we aimed to assess the cardiac tolerance of bevacizumab associated with trastuzumab and chemotherapy in HER2+ breast cancer patients. This is a post-hoc analysis of the BEVERLY-2 study, aiming to assess the efficacy of neoadjuvant bevacizumab, trastuzumab, and chemotherapy for primary inflammatory HER2+ breast cancer. A cohort of 52 patients was prospectively included. Left ventricular ejection fraction (LVEF) was assessed by echocardiography and/or isotopic ventriculography every three months during the mean follow-up of 33±3,42 months. Mean age prior to chemotherapy was 49,75 years ±11,60. On inclusion, mean LVEF was 66,56±6,13.There was no significant difference between LVEF on inclusion and before the 5th cycle of chemotherapy fifth cycle (C5)(66,56%±6,13 vs 65,11%±7,68 ; p=0,24), whereas LVEF was significantly reduced at the end of the neoadjuvant therapy (62,07%±7,84 vs 66,56±6,13; p=0,0001). The nadir of LVEF was 57,87%±8,79 and occured generally during the adjuvant period. In 16 patients, LVEF decreased below 50% after neoadjuvant therapy but complete recovery of LVEF was observed in all at the end of the follow-up, 3 months after the end of the treatment (Figure 1, next page). In this study, with an effective treatment protocol for inflammatory breast cancer, reduction in LVEF was observed in 30% of patients, however, it was reversible in all. Nadir of LVEF was observed after the final adjuvant therapy (31%). This timing and the possibility of recovery should be considered when discussing the interruption of chemotherapy because of reduced LVEF during the follow up. Fig. 1 – Treatment protocol Fig.2 Evolution of LVEF during the follow up Abstract 0380 - Figures 1,2