Population-based demographic study of karyotypes in 1709 patients with adult acute myeloid leukemia.

Few large demographic studies of acute myeloid leukemia (AML) are derived from population-based registries. Demographic and karyotypic data were provided for AML cases from two regional leukemia registry databases in Scotland and the Northern Region of England. A population-based dataset was compiled, comprising 1709 patients aged >16 years (1235 North England/474 Scotland patients). The most common cytogenetic abnormalities involved chromosomes 5 and/or 7 (17%). Patients with the following abnormal chromosome 5/7 combinations: -5, del(5q), -5/-7 and del(5q)/-7 represented a significantly older population (P < 0.01, ANOVA). t(8;21) was the only 'favourable' karyotype found in older age. Karyotypic complexity varied within chromosome 5/7 combination groups; those containing -5, -5/-7, -5/del(7q), del(5q)/-7 or del(5q)/del(7q) combinations were significantly more frequently complex than those containing -7 and del(7q) (P < 0.01, chi2 test). Additional recurring cytogenetic abnormalities within complex karyotypes containing chromosome 5/7 combinations included (in order of frequency), abnormalities of chromosomes 17, 12, 3 and 18. Complex karyotypes not involving chromosomes 5 or 7 represented 30% of all complex karyotypes, occurred in younger patients than those involving chromosomes 5 and 7, and frequently included additional trisomy 8 (26%). In conclusion, we describe subgroups within adverse karyotypes, with different demographics, degree of complexity and additional chromosome abnormalities.