Effect of melatonin cream on acute radiation dermatitis in patients with primary breast cancer: A double-blind, randomized, placebo-controlled trial.

AIM: This was a double-blind, placebo-controlled randomized study investigating whether melatonin can protect against radiation dermatitis in women receiving radiation therapy for primary breast cancer.

METHODS

Patients were included before radiation therapy and followed once weekly throughout treatment with a 3-week follow-up. Patients applied 1 g of cream to the irradiated skin twice daily, consisting of either 25 mg/g melatonin and 150 mg/g dimethyl sulfoxide, or placebo. Our outcomes were the Radiation Therapy Oncology Group's (RTOG) acute radiation morbidity scoring criteria for skin, a pixel analysis of erythema in clinical photographs, and patients' use of corticosteroid cream. Outcomes were evaluated once weekly throughout the trial. The primary outcomes were RTOG-score and pixel analysis at 2 weeks follow-up. Secondary outcomes were the use of corticosteroid cream and analyses of RTOG-scores and pixel analyses throughout the trial.

RESULTS

Sixty-five patients were included, 17 dropped out, totaling 26 and 22 patients randomized to melatonin and placebo, respectively. RTOG-scores and pixel analyses at 2 weeks follow-up showed no difference p = .441 and p = .890, respectively). There was no difference in the use of corticosteroid cream (p = .055). Using logistic regression, the melatonin group had a higher likelihood of having a low RTOG-score (p = .0016). The logistic regression showed no difference between the groups for the pixel analyses.

CONCLUSION

Our primary outcome showed no difference in RTOG-scores at 2 weeks follow-up, however, the RTOG-score over the entire duration of the study demonstrated a protective effect of melatonin. Further studies are warranted investigating higher doses of melatonin, and whether corticosteroids may influence the effect of melatonin cream against radiation dermatitis.