title: Natural history of Southeast Asian chronic myeloid leukemia patients with different BCR-ABL gene variants.
abstract: Little evidence exists regarding the prognostic impact of the major BCR-ABL gene variants (e13a2 and e14a2) in chronic myeloid leukemia (CML) patients diagnosed and treated in the developing Asian countries. In this study, 139 Thai CML patients were followed for a median period of 3 years (range 18-43 months). Clinical presentations of both BCR-ABL gene variant groups (73% e14a2+ and 27% e13a2+) were similar, although e14a2+ patients tended to be older (42 vs. 37 years) and had higher white blood cell counts than e13a2+ patients. The majority of patients in both groups presented with Sokal stage 2-3 (score >0.8) and were categorized as Hasford's intermediate- to high-risk groups (score >780). All patients received oral chemotherapy and 13% underwent allogeneic stem cell transplantation. None received oral tyrosine kinase inhibitors. In the conventional chemotherapy group, the overall survival (OS) rate was slightly better in e14a2+ than in e13a2+ patients (p = n.s.). The median survival in e14a2+ and e13a2+ patients who did not receive stem cell transplantation was 49 and 33 months, respectively (p = n.s.). The type of blastic crisis in e14a2+ and e13a2+ patients was similar, being predominantly myeloid. In conclusion, CML patients in Thailand, despite being much younger, had a comparable OS with those in the Western countries, with no different OS between e14a2+ and e13a2+ patients. Future studies should focus on the impact of novel oral BCR-ABL tyrosine kinase inhibitors on the outcome of Thai CML patients with different BCR-ABL gene variants.
authors.affiliation: Department of Medicine, Division of Hematology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. sciaw@mahidol.ac.th
authors.forename: C U
authors.initials: CU
authors.lastname: Auewarakul
authors.forename: S
authors.initials: S
authors.lastname: Huang
authors.forename: M
authors.initials: M
authors.lastname: Yimyam
authors.forename: S
authors.initials: S
authors.lastname: Boonmoh
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D016313:Genes, abl; D014644:Genetic Variation; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D033581:Stem Cell Transplantation; D013785:Thailand; D014184:Transplantation, Homologous
chemical_list: D016044:Fusion Proteins, bcr-abl