3.4 Other prognostic factors for the survival of pediatric NHL
K-M analysis was also performed to investigate the impact of other clinicopathological features on the survival of pediatric NHL. NHL subtype, CNS involvement, stage, and risk were significantly associated with EFS or OS. Despite there being no significant difference in 5-year OS rate among the four NHL subtypes (BL, 85.9%; DLBCL, 96.4%; LBL 83.5%; ALCL,84.6%; P =0.404;Fig. 3B), the 5-year EFS rate (P = 0.013; Fig. 3A) in ALCL (49.0%) was remarkably lower than that in BL (79.0%; P = 0.021), DLBCL (87.4%; P = 0.005), and LBL (76.7%; P = 0.006). Patients with CNS involvement at diagnosis had a similar 5-year EFS rate (74.7% vs. 69.0%; P = 0.115; Fig. 3C), but had a significantly lower 5-year OS rate (68.5% vs. 87.6%; P = 0.004; Fig. 3D) than those without. Significant differences were found for both the 5-year EFS rate (89.0% vs. 72.2%;P = 0.011;Fig. 4A) and OS rate (100% vs. 83.7%;P = 0.013;Fig. 4B) between patients with early (stage I/II) and advanced (stage III/IV) disease. Patients with early-stage disease had better survival than those with advanced -stage disease. Similarly, the very low/low-risk group had significantly better survival than the intermediate/high-risk group: the 5-year EFS rate was 91.3% and 70.8% (P = 0.002; Fig. 4C), respectively, and the 5-year OS rate was 98.3% and 83.0% (P = 0.009; Fig. 4D), respectively.