3.2 | Disease Classifications and Risk Stratification
ICD-O-3 codes and ICCC-3 were used to further group patients to align
with the BCCSS. In the final analytic survivorship cohort, there were
225 patients with leukemia, 275 with CNS tumors, and 365 patients with
extracranial solid tumor or lymphoma. Based on the BCCSS risk
stratification system,6 there were 191, 496, and 158
low, intermediate, and high risk survivors, respectively.