title: Del(20q) in patients with chronic lymphocytic leukemia: a therapy-related abnormality involving lymphoid or myeloid cells.
abstract: Deletion 20q (Del(20q)), a common cytogenetic abnormality in myeloid neoplasms, is rare in chronic lymphocytic leukemia. We report 64 patients with chronic lymphocytic leukemia and del(20q), as the sole abnormality in 40, a stemline abnormality in 21, and a secondary abnormality in 3 cases. Fluorescence in situ hybridization (FISH) analysis revealed an additional high-risk abnormality, del(11q) or del(17p), in 25/64 (39%) cases. In most cases, the leukemic cells showed atypical cytologic features, unmutated IGHV (immunoglobulin heavy-chain variable region) genes, and ZAP70 positivity. The del(20q) was detected only after chemotherapy in all 27 cases with initial karyotypes available. With a median follow-up of 90 months, 30 patients (47%) died, most as a direct consequence of chronic lymphocytic leukemia. Eight patients developed a therapy-related myeloid neoplasm, seven with a complex karyotype. Combined morphologic and FISH analysis for del(20q) performed in 12 cases without morphologic evidence of a myeloid neoplasm localized the del(20q) to the chronic lymphocytic leukemia cells in 5 (42%) cases, and to myeloid/erythroid cells in 7 (58)% cases. The del(20q) was detected in myeloid cells in all 4 cases of myelodysplastic syndrome. In aggregate, these data indicate that chronic lymphocytic leukemia with del(20q) acquired after therapy is heterogeneous. In cases with morphologic evidence of dysplasia, the del(20q) likely resides in the myeloid lineage. However, in cases without morphologic evidence of dysplasia, the del(20q) may represent clonal evolution and disease progression. Combining morphologic analysis with FISH for del(20q) or performing FISH on immunomagnetically selected sub-populations to localize the cell population with this abnormality may help guide patient management.
authors.affiliation: Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: C Cameron
authors.initials: CC
authors.lastname: Yin
authors.affiliation: Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Guilin
authors.initials: G
authors.lastname: Tang
authors.affiliation: Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Lu
authors.affiliation: Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Feng
authors.affiliation: Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Keating
authors.affiliation: Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: L Jeffrey
authors.initials: LJ
authors.lastname: Medeiros
authors.affiliation: Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Lynne V
authors.initials: LV
authors.lastname: Abruzzo
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects*; D014408:Biomarkers, Tumor / Q000235:genetics*; D002872:Chromosome Deletion; D002890:Chromosomes, Human, Pair 20 / Q000187:drug effects*; D004252:DNA Mutational Analysis; D018450:Disease Progression; D005260:Female; D050438:Genes, Immunoglobulin Heavy Chain; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000188:drug therapy* / Q000235:genetics* / Q000276:immunology / Q000401:mortality; D008214:Lymphocytes / Q000187:drug effects* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D022423:Myeloid Cells / Q000187:drug effects* / Q000276:immunology; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D007135:Immunoglobulin Variable Region