Abstract P5-14-11: Locoregional toxicities after adjuvant radiotherapy with or without concurrent bevacizumab in patients with non-metastatic breast cancer

Abstract

Abstract Purpose/Objectives Few data are available regarding the safety of the concurrent combination of bevacizumab with adjuvant radiotherapy (RT) in breast cancer, especially in terms of late toxicity. The aim of this study was to determine early and late loco-regional toxicities among patients with non-metastatic breast cancer treated with this combination. Materials/Methods In our prospective and descriptive study, we analyzed loco-regional toxicities of adjuvant RT in patients with non-metastatic breast cancer receiving either concurrent bevacizumab or not in the randomized trial BEATRICE. Early and late toxicities were assessed by the Common Terminology Criteria for Adverse Events (v3.0). Evaluation was done during RT and 12 months after the end of RT. All patients provided written informed consent before enrollment. Statistical analysis was performed to analyze toxicity between the two groups. Results From September 2007 to July 2009, we included 84 patients from the randomized trial BEATRICE which evaluate the efficacy and safety of the addition of bevacizumab to standard adjuvant therapy in patients with triple negative breast cancer; 39 women received an adjuvant RT with concurrent bevacizumab and 45 women received an adjuvant RT alone. Evaluation at 12 months was available for all the patients. All patients had a triple negative non-metastatic breast cancer and had an adjuvant chemotherapy then RT. Among patients receiving concurrent bevacizumab with RT, a total of 35 patients (90%) achieved a whole breast irradiation (median dose: 50 Gy) with a boost in the surgical bed (median dose: 16 Gy) and 4 patients (10%) had a post mastectomy RT (median dose 50 Gy); lymph node RT was performed in 19 patients (49%) with internal mammary chain RT in 12 patients (31%). Mean time of bevacizumab treatment was 11.7 months [2.1-12.6] and mean total dose of bevacizumab was 15000 mg [3330-28080]. Among patients receiving RT alone, 38 patients (84%) achieved a whole breast irradiation (median dose: 50 Gy) with a boost in the surgical bed (median dose: 16 Gy) and 7 patients (16%) had a post mastectomy RT (median dose 50 Gy); lymph node RT was performed in 21 patients (47%) with internal mammary chain RT in 14 patients (31%). Radiation treatment parameters were not significantly different between the two groups. Incidence of acute grade 3 dermatitis was 10% in patients receiving bevacizumab associated with RT and 6% in patients receiving RT alone without significant difference. One year after the end of RT, the most common late toxicities in the group receiving bevacizumab and RT were grade 1-2 pain (18%), grade 1-2 fibrosis (8%), grade 1-2 arm lymphedema (8%) and grade 1-2 telangiectasia (6%).There was no significant difference in pain, radiation fibrosis, telangiectasia, arm lymphedema and dyspnea between the two groups. No patient experienced grade 3-4 toxicity in the two groups. Conclusions Our results indicate that concurrent bevacizumab with loco-regional RT provide acceptable early and late toxicities after one year in patients with non-metastatic breast cancer. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-11.