Definition of treatment groups

Treatment intensity was divided into 4 categories: full-dose R-CHOP, attenuated R-CHOP, anthracycline-free regimen, and no chemotherapy. Patients were assigned to a category based on “planned treatment,” here defined by the regimen and dosing given at the first cycle. Doxorubicin was used to define R-CHOP dosage, and the cutoff for attenuated R-CHOP was set at an initial doxorubicin dose ≤80% of the standard dose (50 mg/m²) based on cutoffs used in the literature,^31-35 clinical reasoning, and the distribution of dose reductions in our cohort. Further details are provided in supplemental Methods.