PGR and dermatological toxicity: For 4–5 versus 0–1, higher BMI (OR = 2.99, 95% CI = 1.29, 6.92), ER‐positive/PR‐negative status (OR = 3.50, 95% CI = 1.29, 9.48), and conventionally fractionated regimens (OR = 4.81, 95% CI = 1.77, 13.05) were significantly associated with higher grade skin toxicity‐ specifically moist desquamation.