Effect of addition of R (rituximab) to CHOP remission induction on progression-free survival and overall survival. Kaplan-Meier plots of progression-free survival and overall survival from first randomization. (A) Progression-free survival after CHOP (n = 231) and R-CHOP (n = 234) remission induction treatment. (B) Overall survival after CHOP (n = 231) and R-CHOP (n = 234) remission induction treatment.