EFS and OS. (A) Kaplan-Meier with associated log-rank test for EFS for the entire cohort (P < .001; n = 136), comparing patients with a proportion of IL-6⁺ leukocytes ≥1% vs IL-6⁺ leukocytes <1%. (B) Forest plot for EFS performed with multivariate Cox regression (n = 107); 29 observations were deleted due to missing values in covariate variables. (C) The same as panel A, but for OS (n = 136; P < .001). (D) Forest plot as in panel B but for OS. (E) Kaplan-Meier for OS after propensity score matching with an illustration of unbalanced and balanced populations after adjustment (Caliper = 0.2). Adjusted items in the propensity score matching: age ≥45 years (yes/no); advanced-stage disease > IIB (yes/no); B symptoms (yes/no); albumin <4 g/L (yes/no); erythrocyte sedimentation rate (ESR) ≥50 mm/h (yes/no); IPS ≥2. After deleting missing values and balancing the covariates, a matched homogenous sample size of 32 of 32 (n = 64) was compared. WBC, white blood count.