Kaplan-Meier curves showing survival for different cytogenetic abnormalities. (A) Event-free survival of children with iAMP21 treated as standard risk on the UK childhood ALL trial ALL97/99 (n = 28) compared with those treated as high risk on ALL2003 (n = 53). (B) Event-free survival of childhood BCP-ALL patients from ALL97/99 according to cytogenetic risk groups (adapted from Moorman et al³ ). Good risk includes high hyperdiploidy and ETV6-RUNX1; poor risk includes t(9;22)(q34;q11.2), iAMP21, MLL translocations, near haploidy, low hypodiploidy, t(17;19)(q23;p13), abnormal 17p, and loss of 13q; intermediate risk includes normal karyotype and all other abnormalities. (C) Overall survival of adults with ALL treated on the adult trial UKALLXII/ECOG2993 (adapted from Moorman et al⁵ ). Percentages are overall survival at 7 years. High-risk abnormalities include: t(4;11)(q21;q23), IGH@ translocations, CRLF2 rearrangements, low hypodiploidy/near-triploid, and complex karyotype. Philadelphia positive/t(9;22)(q34;q11) patients were sufficiently prevalent to be shown separately. Standard risk includes all other abnormalities. The improved outcome of high hyperdiploidy is indicated separately.