Predictive factors for late normal tissue complications following radiotherapy for breast cancer

Abstract

Radiotherapy after breast-conserving surgery is commonly applied to reduce recurrence of breast cancer but may cause acute and late side effects. To identify prognostic factors for the development of late toxicity after radiotherapy, we conducted a prospective study of breast cancer patients. We assessed late complications of radiotherapy and collected information on epidemiologic factors in a cohort of breast cancer patients who had received radiotherapy after breast-conserving surgery. Among 416 patients with complete follow-up data, the association between possible risk factors and development of late complications was evaluated using multivariate logistic regression analysis. After a median follow-up time of 51 months, 131 (31.4%) patients presented with telangiectasia and 28 (6.7%) patients with fibrosis. We observed a strong association between development of telangiectasia and fibrosis (p < 0.01). Increasing age of the patient was a risk factor for both telangiectasia and fibrosis (p-value for trend <0.01 and 0.03, respectively). Patients with acute skin toxicity (odds ratio (OR) 1.8, 95% confidence interval (CI) 1.0–3.1) were at higher risk to develop telangiectasia. Long-term smoking was associated with a significant increase in risk of telangiectasia compared to non-smokers (OR 2.3, 95% CI 1.2–4.6). Our study revealed several factors other than radiation dose that may predispose to late complications following radiotherapy. Further understanding of differences in response to irradiation may advance individualized treatment and improve cosmetic outcome.