Hypofractionated radiotherapy and adjuvant chemotherapy do not increase radiation-induced dermatitis in breast cancer patients

Purpose Radiation-induced dermatitis is a common side effect of breast irradiation, with hypofractionation being a well-known risk factor. In the context of the widespread adoption of hypofractionated breast radiotherapy, we evaluated the effect of hypofractionated radiotherapy on the incidence of skin toxicity in patients receiving adjuvant chemotherapy. Patients and Methods We retrospectively reviewed the records of patients with breast cancer treated from 2004 to 2006 at a single institution. Patients undergoing lumpectomy with or without adjuvant chemotherapy followed by hypofractionated radiotherapy consisting of 42.4 Gy in 16 fractions were included in the study. Using cosmetic and skin toxicity scales, all patients were evaluated weekly during treatment and at scheduled follow-up visits with the radiation oncologist. Results During the study period, 162 patients underwent radiotherapy, and 30% of those (n = 48) received chemotherapy. Radiotherapy boost to the tumour bed was more common in the chemotherapy group [n = 20 (42%)] than in the radiotherapy-alone group [n = 30 (26%)]. We observed no statistically significant difference between the groups with regard to acute skin toxicity of grade 3 or higher (2.1% in the chemotherapy group vs. 4.4% in the radiation-alone group, p = 0.67) or of grades 1-2 toxicity (62.5% vs. 51.7% respectively, p = 0.23). There was also no significant difference in late grade 3 or higher skin toxicity between the groups (2.1% vs. 0% respectively, p = 0.30) or in grades 1-2 toxicity (20.8% vs. 25.5% respectively, p = 0.69). Similarly, excellent or good cosmetic result scores were similar in both groups (p = 0.80) Conclusions In our single-institution review, we observed no adverse effects of chemotherapy in combination with hypofractionated whole-breast irradiation. Further investigations are necessary to better elucidate the effects of chemotherapy on skin toxicity in the context of hypofractionated irradiation.