An unrelated Clone of 20q Deletion Following Successful Treatment of Leukemia in Patients with t(8;21), t(15;17) or t(9;22) / 임상검사와정도관리

ABSTRACT

Cases of clonal cytogenetic abnormalities in Philadelphia-negative cells during the treatment of Philadelphia-positive CML have been previously reported. However, clonal abnormalities unrelated to the original t(8;21) or t(15;17) karyotype are not common. Deletion of 20q (del(20q)) is one of the most common recurrent cytogenetic abnormalities in myeloid neoplasms. Here we describe 3 patients with t(8;21), t(15;17), or t(9;22) who developed unrelated del(20q) after successful treatment of leukemia. We retrospectively reviewed the cytogenetic results of 23 AML patients with t(8;21)(q22;q22), 28 AML patients with t(15;17)(q22;q12), and 47 CML patients with t(9;22)(q34;q11.2). We identified 3 patients with del(20q) as the only clonal aberration unrelated to the primary karyotype when they achieved complete morphologic and cytogenetic remission. The latency period between diagnosis and emergence of del(20q) was 1, 114, and 35 months for the 3 patients, respectively. There was no evidence of therapy-related MDS/AML during the follow-up period. In 1 AML patient with t(8;21), relapse occurred in a t(8;21)(q22;q22) clone and the del(20q) clones were lost. The clinical significance of del(20q) as an unrelated clonal aberration is unknown, but our study suggests that del(20q) does not cause therapy-related MDS/AML or indicate disease progression.