The acute skin and heart toxicity of a concurrent association of trastuzumab and locoregional breast radiotherapy including internal mammary chain: a single-institution study.

Abstract Background To evaluate the skin and heart toxicity of a concurrent adjuvant trastuzumab-radiotherapy for breast cancer (BC), especially in the case of internal mammary chain (IMC) irradiation. Material and methods Prospective study of 106 patients treated between 06/2003 and 03/2007 by concurrent trastuzumab-radiotherapy for non-metastatic BC. Left ventricular ejection fractions (LVEF) was assessed at baseline, before and after radiotherapy and then every 4–6 months. All toxicities were evaluated using CTCAEV3. Results Median age was 52 years (25–76). Chemotherapy with anthracycline was administered in 92% of patients. All patients received trastuzumab every three weeks (8 mg/kg followed by 6 mg/kg) for a median duration of 12 months (3-40). The IMC was irradiated in 83% of patients. There were: 87 grade 1, 14 grade 2 and 2 grade 3 skin reactions. There were 13 oesophagitis: 9 grade 1; 3 grade 2, and 1 grade 3. Out of 101 patients with assessments after 6 months, late telangiectasia grade 1 occurred in 5 patients, local pain grade 1 in 19 patients and grade 2 in 3 patients, fibrosis grade 1 in 16 patients. A reversible grade ⩾2 left ventricular systolic dysfunction occurred in 6 patients. Conclusion In this prospective study of breast cancer patients treated with trastuzumab-radiotherapy with, in most cases, anthracycline-based chemotherapy and IMC irradiation, both the rate of abnormal LVEF after concurrent trastuzumab-radiotherapy and the skin toxicity were deemed acceptable. Further follow-up is needed.