The characteristics and prognostic analysis in 213 myeloid malignancy patients with del(20q): a report of a single-center case series.

The clinical and hematological characteristics and the prognostic significance of del(20q) were investigated in a consecutive series of 213 myeloid malignancies. In the analyses, the cases were divided into three subgroups according to diagnosis or four subgroups according to cytogenetic data. Patients in the myeloproliferative neoplasms subgroup had high WBCs and platelet counts at initial diagnosis. The del(20q) occurred predominantly in older men. Sole del(20q) was observed most often in myelodysplastic syndromes, while del(20q) as a part of complex karyotypes was observed predominantly in acute myeloid leukemia. The most frequent additional abnormalities accompanying del(20q) were -5/del(5q), -7/del(7q) and +8; t(20;21)(q11;q11) and double del(20q) were two rare but recurrent abnormalities secondary to del(20q). In all types of diseases, patients with a sole del(20q) had a favorable prognosis. The presence of any additional abnormality with del(20q) had an unfavorable outcome. Patients with i(20q) had an unfavorable prognosis. Patients with the minor del(20q) clone had a better median survival than those with the major del(20q) clone.