ABSTRACT
We conducted a retrospective population-based study of patients diagnosed with acute myeloid leukemia (AML) in northern England (population 3.1 million) in order to assess the impact of age and genetics on outcome. Four hundred and sixteen patients were diagnosed with AML, between 2007 and 2011. In those aged ≤60 years (n = 20) with acute promyelocytic leukemia (APL) overall survival (OS) was 100%. For non-APL patients aged ≤60 years, OS for those with favorable, intermediate and adverse cytogenetics was not reached, 17 and 9.8 months, respectively (p = 0.0001). Of particular note, intensively treated patients aged >60 years with intermediate cytogenetics and FLT3-/NPM1+ status had a five-year survival of 60% versus median OS of 11 months for other subsets (p = 0.04). Population-based studies reduce selection bias and have utility in studying rarer diseases, particularly in populations that recruit poorly to trials. The highly favorable outcome in our subgroup of intensively-treated FLT3-/NPM1+ older patients merits further study.
Subject(s)
Leukemia, Myeloid, Acute/epidemiology , Adult , Aged , Aged, 80 and over , Chromosome Aberrations , Combined Modality Therapy , England/epidemiology , Female , Genetic Predisposition to Disease , Humans , Incidence , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/therapy , Male , Middle Aged , Mutation , Nucleophosmin , Outcome Assessment, Health Care , Population Surveillance , Prognosis , Retrospective Studies , Young AdultABSTRACT
Fusion genes derived from the platelet-derived growth factor receptor beta (PDGFRB) or alpha (PDGFRA) play an important role in the pathogenesis of BCR-ABL-negative chronic myeloproliferative disorders (CMPDs). These fusion genes encode constitutively activated receptor tyrosine kinases that can be inhibited by imatinib. Twelve patients with BCR-ABL-negative CMPDs and reciprocal translocations involving PDGFRB received imatinib for a median of 47 months (range, 0.1-60 months). Eleven had prompt responses with normalization of peripheral-blood cell counts and disappearance of eosinophilia; 10 had complete resolution of cytogenetic abnormalities and decrease or disappearance of fusion transcripts as measured by reverse transcriptase-polymerase chain reaction (RT-PCR). Updates were sought from 8 further patients previously described in the literature; prompt responses were described in 7 and persist in 6. Our data show that durable hematologic and cytogenetic responses are achieved with imatinib in patients with PDGFRB fusion-positive, BCR-ABL-negative CMPDs.
Subject(s)
Antineoplastic Agents/therapeutic use , Fusion Proteins, bcr-abl/blood , Myeloproliferative Disorders/drug therapy , Oncogene Proteins, Fusion/blood , Piperazines/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Pyrimidines/therapeutic use , Receptor, Platelet-Derived Growth Factor beta/blood , Adult , Aged , Aged, 80 and over , Benzamides , Biomarkers, Tumor/blood , Child , Child, Preschool , Drug Evaluation , Eosinophilia/etiology , Female , Follow-Up Studies , Humans , Imatinib Mesylate , Infant , Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/blood , Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/drug therapy , Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative/genetics , Male , Middle Aged , Myeloproliferative Disorders/blood , Myeloproliferative Disorders/genetics , Oncogene Proteins, Fusion/genetics , RNA, Messenger/blood , RNA, Neoplasm/blood , Receptor, Platelet-Derived Growth Factor beta/genetics , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , Translocation, Genetic , Treatment OutcomeABSTRACT
The BCR-ABL-negative chronic myeloproliferative disorders (CMPD) and myelodysplastic/myeloproliferative diseases (MDS/MPD) are a spectrum of related conditions for which the molecular pathogenesis is poorly understood. Translocations that disrupt and constitutively activate the platelet-derived growth factor receptor beta(PDGFRB) gene at chromosome band 5q33 have been described in some patients, the most common being the t(5;12)(q33;p13). An accurate molecular diagnosis of PDGFRB-rearranged patients has become increasingly important since recent data have indicated that they respond very well to imatinib mesylate therapy. In this study, we have tested nine patients with a CMPD or MDS/MPD and a translocation involving 5q31-33 for disruption of PDGFRB by two-colour fluorescence in situ hybridization (FISH) using differentially labelled, closely flanking probes. Normal control interphase cells gave a false positive rate of 3% (signals more than one signal width apart). Six patients showed a pattern of one fused signal (from the normal allele) and one pair of signals separated by more than one signal width in > 85% of interphase cells, indicating that PDGFRB was disrupted. These individuals had a t(1;5)(q21;q33), t(1;5)(q22;q31), t(1;3;5)(p36;p21;q33), t(2;12;5)(q37;q22;q33), t(3;5) (p21;q31) and t(5;14)(q33;q24) respectively. The remaining three patients with a t(1;5)(q21;q31), t(2;5)(p21;q33) and t(5;6)(q33;q24-25) showed a normal pattern of hybridization, with > or = 97% interphase cells with two fusion signals. We conclude that two-colour FISH is useful to determine the presence of a PDGFRB rearrangement, although, as we have shown previously, this technique may not detect subtle complex translocations at this locus. Our data indicate that several PDGFRB partner genes remain to be characterized.
