Hypofractionated whole breast radiotherapy with or without hypofractionated boost in early stage breast cancer patients: a mono-institutional analysis of skin and subcutaneous toxicity

BackgroundOur study evaluated skin and subcutaneous toxicity analyzing its correlation with patient- and treatment-related factors in a large mono-institutional series of women with early stage breast cancer treated with adjuvant hypofractionated whole breast radiotherapy (WBRT) with or without a sequential hypofractionated boost (HB).MethodsTwo hundred and nineteen patients, median age 62years, received adjuvant hypofractionated WBRT in 16 fractions to a total dose of 42.4Gy. Patients with negative prognostic factors received a HB of 2.65Gy for 4 or 5 (patients with focal positive surgical margins) fractions. Systemic adjuvant treatments were hormonal therapy (HT) and/or chemotherapy (CHT) and/or Trastuzumab. Toxicities were assessed using the Common Terminology Criteria for Adverse Events (CTCAE 4.03) scale at 5th, 10th, 16th, 20th day from the start of radiotherapy (RT) and 1, 6 and 12months after the end of RT. Univariate and multivariate analysis estimated toxicity predictive factors.ResultsNo case of treatment interruption and no acute or late G3 toxicities occurred. In the univariate analysis HB administration resulted a risk factor for acute toxicity, while CHT administration and number of excised lymph nodes10 resulted a risk factor for late toxicity. In the multivariate analysis none of the evaluated factors emerged a risk factor for acute and/or late toxicity.ConclusionsOur results confirmed that hypofractionated WBRT even followed by a HB resulted safe and well tolerated. Longer follow-up is warranted to estimate late toxicity and treatment outcomes.