Topical silymarin administration for prevention of acute radiodermatitis in breast cancer patients: A randomized, double-blind, placebo-controlled clinical trial.

Radiation-induced dermatitis is one of the most common side effects of radiotherapy. Silymarin, a flavonoid extracted from the Silybum marianum, exhibits antioxidant and anti-inflammatory activities. The purpose of this study was to investigate the efficacy of silymarin gel in prevention of radiodermatitis in patients with breast cancer. During this randomized, double-blinded, placebo-controlled clinical trial, the preventive effect of silymarin 1% gel was assessed in comparison with placebo, on radiodermatitis occurrence. Forty patients randomly received silymarin gel or placebo formulation on chest wall skin following modified radical mastectomy, once daily starting at the first day of radiotherapy for 5 weeks. Radiodermatitis severity was assessed weekly based on Radiation Therapy Oncology Group (RTOG) and National Cancer Institute Common Terminology for Adverse Events (NCI-CTCAE) criteria radiodermatits grading scale for 5 weeks. The median NCI-CTCAE and RTOG scores were significantly lower in silymarin group at the end of the third to fifth weeks (p value < 0.05). The scores increased significantly in both placebo and silymarin groups during radiotherapy, but there was a delay in radiodermatitis development and progression in silymarin group. Prophylactic administration of silymarin gel could significantly reduce the severity of radiodermatitis and delay its occurrence after 5 weeks of application.