Dietary Macronutrient Composition and Risk of Radiation-Induced Acute Skin Toxicity in Women with Breast Cancer:...

The impact of the dietary macronutrient composition and its subcomponents (saccharides, fatty acids, and protein sources) on radiation-induced acute skin toxicity (AST) in breast cancer (BC) patients is unknown. Hence, we examined the association between dietary macronutrients and their subcomponents and the risk of ≥grade 2 (G2) AST post-radiotherapy among women with BC.

An observational study was conducted among 161 BC patients treated with radiotherapy and enrolled in the ATHENA project in Italy. Habitual dietary intake was assessed at study entry (T0) using a 188-item food frequency questionnaire (FFQ). AST was measured at T1 (after 3 or 5 weeks of radiotherapy) and defined according to the Radiation Therapy Oncology Group criteria. A prospective analysis used multivariable-adjusted logistic regression models to examine the association between the dietary macronutrient composition and its subcomponents at T0 and the odds of ≥G2 AST post-radiotherapy.

≥G2 AST post-radiotherapy was observed in 43 (27%) patients. Among dietary macronutrient models, a higher intake of dietary carbohydrates was positively associated with a 30% higher odds of ≥G2 AST post-radiotherapy (OR = 1.30; 95% CI 1.01 to 1.67; for 30 g/d). Conversely, a higher dietary protein intake was inversely associated with a 76% lower odds of ≥G2 AST post-radiotherapy (OR = 0.24; 95% CI 0.06 to 0.91; for 30 g/d). There was no association with dietary fat. In macronutrient subcomponent models, only animal protein was inversely associated with a 51% lower odds of ≥G2 AST post-radiotherapy (0.49; 95% CI 0.25 to 0.95; for 15 g/d).

Dietary carbohydrates were associated with a higher risk of radiation-induced AST among women with BC, whereas dietary protein, especially animal protein, was associated with a lower risk. Cautiously balancing carbohydrate and protein intakes could be a part of the clinical management strategy for ≥G2 AST reduction post-radiotherapy among BC women.