OBJECTIVETo delineate the clinical features and prognostic significance of acquired trisomy 21 (+21) in 31 patients with acute myeloid leukemia (AML).

METHODSChromosome specimen was prepared from bone marrow samples using a direct method and (or) cultivation, and their karyotypes were analyzed with R banding. The clinical features, chemotherapeutic effect and survival status of patients with acquired +21 were evaluated.

RESULTSCytogenetic studies were successfully performed on 3 329 patients with newly diagnosed AML, among which 31 (0.93%) had acquired +21. And 16 (0.48%) of the 31 patients had +21 as the sole abnormality. The most frequent subgroup of bone marrow morphology was AML-M5b, and its total number was 12 (38.7%) of the total. Thirty patients among those with +21 received standard chemotherapy. The complete remission (CR) rate (63% vs. 80%, P< 0.05) and median overall survival (OS) (7 months vs. 15 months, P< 0.01) of AML patients with acquired +21 were both lower than those without. Age (60 years or older) was associated with a significantly lower CR rate (30% vs. 80%, P< 0.05) and shorter median OS (4 months vs. 12 months, P< 0.01). Comparing to acquired +21 with other additional abnormalities, acquired +21 solely was associated with a lower median OS (6 months vs. 12 months, P< 0.05), but did not affect the CR rate (60% vs. 67%, P> 0.05). Three patients undergoing allogenetic hematopoietic stem cell transplantation (allo-HSCT) were still alive at the end of follow-up. Their survival time have reached 56, 36 and 105 months, respectively, which were remarkably longer than those only received chemotherapy (P< 0.01).

CONCLUSIONThe presence of acquired +21 in patients with AML has a adverse prognosis with or without other additional abnormalities. Older age (60 years or older) and +21 alone predicted relatively poorer outcome. Allo-HSCT was expected to prolong the survival time of AML patients with acquired +21.