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.