EFS and OS by patient age group. Analyzing the survival rates by patient age groups (16-35, 36-55, and 56-65 years), the probability of 3-year EFS and OS were as follows: for EFS, 71% (95% CI, 52-83) vs 50% (95% CI, 32-66) vs 23% (95% CI, 6-48; P = .001); and for OS, 85% (95% CI, 68-94) vs 69% (95% CI, 50-82) vs 46% (95% CI, 20-70; P < .001), respectively.