The effect of washing the irradiated skin during radiotherapy for breast cancer is uncertain. The purpose of this study was to evaluate the impact of washing the breast skin with water and soap during radiotherapy on the intensity of acute skin toxicity.

Ninety-nine patients treated for breast cancer were prospectively randomized prior to receiving radiotherapy to the breast into two groups: (1), no washing was allowed during radiotherapy (49 patients); and (2), washing was allowed with water and soap (50 patients). Acute toxicity was recorded according to the Radiation Therapy Oncology Group (RTOG) acute skin toxicity scale for each patient every week during radiotherapy and 1 month after the end of radiotherapy. Symptoms related to skin toxicity were scored by visual analogue scales at the same time intervals. Other data collected included sociodemographic data, characteristics related to the tumor and previous treatments, radiation technique, necessity for a second simulation due to loss of skin marks and treatment interruptions.

In the non-washing group, the following maximum acute toxicity scores were observed: grade 0, 2%; grade 1, 41%; grade 2, 57%; grades 3 and 4, 0%. For the washing group, the scores were: grade 0, 0%; grade 1, 64%; grade 2, 34%; grade 3, 2%; and grade 4, 0%. Moist desquamation was seen in 33% of non-washing patients, but in only 14% of washing patients. The median scores of pain, itching and burning of the treated skin were higher in the non-washing group, although this was not statistically significant. In a multivariate analysis using logistic regression, acute skin toxicity was associated with the patient's weight, concomitant radiochemotherapy and hot spots on dosimetry, and there was a trend toward more acute skin toxicity in the non-washing group.

Washing the irradiated skin during the course of radiotherapy for breast cancer is not associated with increased skin toxicity and should not be discouraged.