The Impact of Obesity on Acute Skin Toxicity from Radiation Treatment for Breast Cancer: Opportunities to Predict and Address

Rationale: As radiation therapy techniques have improved, skin toxicity from breast radiation is less common. However, as the rates of metabolic syndrome and obesity increase, we sought to determine the impact of obesity on acute skin toxicity following radiation therapy for early-stage breast cancer and explored potential strategies for mitigating toxicity. Objectives: A retrospective analysis was conducted on 355 early-stage breast cancer patients who underwent radiation therapy. Patient demographics, clinical characteristics, radiation details, and skin toxicity were recorded. Logistic regression models were used to assess the association between obesity (BMI ≥ 30) and skin toxicity, considering treatment variables such as radiation dose, boost, and wedge use. Findings: Higher BMI was significantly associated with increased odds of grade 2 or higher skin toxicity (OR = 4.24, p < 0.001). The use of wedges showed a potential protective effect against toxicity in overweight patients (OR = 0.48, p = 0.060). Multivariable analysis revealed that younger age, higher BMI, and an increased number of radiation segments were associated with a higher likelihood of toxicity. Recurrence rates did not differ significantly between BMI groups. Conclusion: Obesity is a significant risk factor for acute skin toxicity in breast cancer patients undergoing radiation therapy. Strategies to mitigate toxicity, such as personalized treatment planning incorporating wedges and optimizing radiation dose, are crucial for improving patient outcomes. Future research is warranted to explore the role of dietary interventions or personalized therapies to minimize acute radiation toxicity for patients living with metabolic dysfunction or obesity.