Seasonal Impact on Grade ≥2 Dermatitis in Patients With Breast Cancer Undergoing Radiotherapy: A Supplementary Analysis

Abstract

Background/aim: We investigated grade ≥2 dermatitis in patients irradiated for breast cancer. This study evaluated associations between dermatitis and the season during which radiotherapy took place.

Patients and methods: Associations between the season and grade ≥2 dermatitis were retrospectively evaluated in 327 breast cancer patients. Seasons were March to May (spring), June to August (summer), September to November (autumn), and December to February (winter). Subgroup analyses were performed considering fractionation, radiation technique, treatment volume, radiation boost, and deep-inspiration breath-hold technique. Furthermore, warmer and cooler months were compared.

Results: The season had no significant impact on the rate of grade ≥2 dermatitis in the entire cohort (p=0.63) nor in the subgroup analyses (p-values between 0.17 and 0.82). No significant difference in rate was found between warm and cool months.

Conclusion: Grade ≥2 dermatitis was not associated with the season during which radiotherapy was performed. This factor may not be important for stratification in prospective trials.

Keywords: Breast cancer; adjuvant irradiation; grade ≥2 radiation dermatitis; season of treatment.