Transforming growth factor beta 1 levels predict echocardiographic changes at three years after adjuvant radiotherapy for breast cancer

Abstract Background Transforming growth factor beta 1 (TGF-β1) and platelet-derived growth factor (PDGF) are cytokines involved in fibrotic processes causing radiotherapy (RT)-induced cardiovascular changes. We aimed to investigate the associations between TGF-β1 and PDGF and the echocardiographic changes that occur during RT and during three-year follow-up. Methods The study included 63 women receiving adjuvant RT for early-stage breast cancer or ductal carcinoma in situ. Serum TGF-β1 (ng/ml) and PDGF (ng/ml) levels were measured by enzyme-linked immunoassay and echocardiographic examination was performed before RT, after RT and at 3 years. Patients were grouped by biomarker behavior by a trajectory analysis. Results TGF-β1 decreased from 19.2 (IQR 17.1–22.3) before RT to 18.8 (14.5–22.0) after RT (p = 0.003) and the decrease persisted at 17.2 (13.7–21.2) 3 years after RT (p = 0.101). PDGF decreased from 15.4 (12.6–19.1) before RT to 13.8 (11.7–16.2) after RT, p = 0.001, and persisted at 15.6 (10.4–18.4) at 3 years, p = 0.661. The TGF-β1 level before RT (Spearman’s rho 0.441, p