Late toxicities and outcomes of adjuvant radiotherapy combined with concurrent bevacizumab in patients with triple-negative non-metastatic breast cancer

Objective: To evaluate the safety of the concurrent combination of bevacizumab with adjuvant radiotherapy (B-RT) in breast cancer (BC). Methods: Multicentre, prospective study, of the toxicity of adjuvant radiotherapy (RT) alone or B-RT in patients with non-metastatic BC enrolled in randomized Phase 3 BEATRICE trial. Early and late toxicities were assessed by the Common Terminology Criteria for Adverse Events v. 3.0 during and 12 months after the completion of RT. Results: From 2007 to 2012, 39 females received adjuvant B-RT and 45 received adjuvant RT alone. Median follow-up was 21.5months. All patients had triple-negative non-metastatic BC and received adjuvant chemotherapy followed by RT. 90% of the 39 females treated by concurrent B-RT received whole breast irradiation (WBI) with a boost and 4 (10%) received post-mastectomy RT. Lymph node RT was delivered in 49% of the females with internal mammary chain irradiation. The mean duration of bevacizumab was 11.7 months. 38 (84%) females treated by RT alone received WBI with a boost and 16% of the females received post-mastectomy RT. Lymph node RT was delivered in 47% of the females with internal mammary chain RT in 31%. Grade 3 acute dermatitis was observed in 9% of patients receiving B-RT and 5% of patients receiving RT alone with no significant difference. 1 year after the completion of RT, the most common late grade 1-2 toxicities in the B-RT group were pain (18%), fibrosis (8%) and telangiectasia (5%). Conclusion: The concurrent bevacizumab with locoregional RT is associated with acceptable early and late 1-year toxicities in patients with BC. Advances in knowledge: The largest series of this association.