The incidence of trisomy 8 as a sole chromosomal aberration in myeloid malignancies varies in relation to gender, age, prior iatrogenic genotoxic exposure, and morphology.

Although trisomy 8 as a sole change is one of the most common chromosomal abnormalities in myeloid malignancies, it is largely unknown if the incidence of this aberration is influenced by other factors of clinical importance. In the present study, the frequencies of isolated +8 in relation to gender, age, previous treatment with chemo- or radiotherapy, and morphologic subtype were ascertained in published, as well as in our own unpublished, cases of acute myeloid leukemia (AML; n=4,246), myelodysplastic syndromes (MDS; n=1,817), and chronic myeloproliferative disorders (MPD; n=530). The frequencies of +8 were higher in MDS and MPD than in AML (7.5% vs. 5.6%; P<0.01) and varied among the morphologic subtypes of AML and MDS (P<0.001 and P<0.05, respectively). Trisomy 8 was more common in women than in men with MPD (11% vs. 5.1%; P<0.05). Furthermore, the frequencies of +8 were higher in de novo AML and MDS than in treatment-related cases (6.0% vs. 2.8%; P<0.01 and 8.6% vs. 1.5%; P<0.001, respectively). The incidence also varied significantly with age in AML (P<0.001), being more common in elderly patients. Although the causes for this frequency heterogeneity remain to be elucidated, possible explanations may include different environmental exposures affecting the origin of +8 in AML, MDS, and MPD and the presence of different underlying cryptic primary aberrations.