Five-year probability of OS in Burkitt lymphoma/leukemia patients according to risk factors. (A) Five-year probability of OS according to IPI score: 0-2 (n = 140), 0.90 ± 0.03; 3-5 (n = 146), 0.75 ± 0.04 (P = .0005). (B) Five-year probability of OS according to aaIPI score; 0-1 (n = 111), 0.93 ± 0.03; 2-3 (n = 192), 0.74 ± 0.03 (P < .0001). (C) Five-year probability of OS according to age: 15 to 25 years (n = 69), 0.90 ± 0.04; 26 to 55 years (n = 196), 0.84 ± 0.03; >56 years (n = 98), 0.62 ± 0.05 (P < .0001). (D) Five-year probability of OS according to age >55 years: 55 to 59 years (n = 19), 0.56 ± 0.12; 60 to 65 years (n = 34), 0.71 ± 0.08; 66 to 70 years (n = 30), 0.68 ± 0.09; >70 years (n = 15), 0.43 ± 0.14 (P = .3). (E) Five-year probability of OS according to gender: male (n = 253), 0.84 ± 0.02; female (n = 110), 0.70 ± 0.05 (P = .004).