Citations

A multicenter Eastern Cooperative Group (ECOG) phase 2 trial assessed whether adding prednisone to lenalidomide would improve previously reported responses in persons with myelofibrosis (MF). Forty-eight subjects with anemia (42 evaluable) received lenalidomide, 10 mg/d, with a 3-month low-dose prednisone taper. Ten subjects received 3 months, and 25 received 6 months of therapy. Myelosuppression was the main toxicity with 88% with ≥ grade 3 hematologic toxicity and 45% ≥ grade 3 nonhematologic toxicity. There were responses in 10 subjects (23%) using the International Working Group for Myelofibrosis Research and Treatment (IWG-MRT)–defined clinical improvement of anemia in 8 (19%) and/or decreased spleen size in 4 (10%). Serial bone marrow analysis showed no resolution of disease-related fibrosis or angiogenesis. With a median follow-up of 2.3 years, 23 subjects are alive. Lenali-domide and prednisone for myelofibro-sis evaluated through a multicentered-cooperative group mechanism is only modestly active and myelosuppre-sive. This study was registered at http://clinicaltrials.gov as NCT00227591.

Abstract The prognostic heterogeneity of the World Health Organization category of “systemic mastocytosis with associated clonal hematologic nonmast cell lineage disease” (SM-AHNMD) has not been systematically validated by primary data. Among 138 consecutive cases with SM-AHNMD, 123 (89%) had associated myeloid neoplasm: 55 (45%) myeloproliferative neoplasm (SM-MPN), 36 (29%) chronic myelomonocytic leukemia, 28 (23%) myelodysplastic syndrome (SM-MDS), and 4 (3%) acute leukemia. Of the myeloid subgroups, SM-MPN displayed a 2- to 3-fold better life expectancy (P = .003), whereas leukemic transformation was more frequent in SM-MDS (29%; P = .02). The presence of eosinophilia, although prevalent (34%), was prognostically neutral, and the overall results were not affected by exclusion of FIP1L1-PDGFRA-positive cases. We conclude that it is clinically more useful to consider specific entities, such as SM-MPN, systemic mastocytosis with chronic myelomonocytic leukemia, SM-MDS, and systemic mastocytosis with-acute leukemia, rather than their broad reference as SM-AHNMD.

We thank you for calling our attention to the comments made by Professor Biersack on our paper (Huang et al, 1987) concerning the diagnostic significance of liver and spleen scans in systemic mast-cell disease (SMCD).

Abstract Clinical phenotype in systemic mastocytosis (SM) is markedly variable, which complicates prognostication and decision making regarding the choice and timing of therapy. In a retrospective study of 342 consecutive adult patients with SM seen at the Mayo Clinic between 1976 and 2007, disease subdesignation according to the World Health Organization (WHO) proposal was indolent (ISM) in 159 (46%), with associated clonal hematologic non–mast cell lineage disease (SM-AHNMD) in 138 (40%), aggressive (ASM) in 41 (12%), and mast cell leukemia in 4 (1%). KITD816V was detected in bone marrow–derived DNA by allele-specific polymerase chain reaction (PCR) in 68% of 165 patients evaluated (ISM, 78%; ASM, 82%; SM-AHNMD, 60%; P = .03); JAK2V617F was detected in 4%, all in SM-AHNMD. Compared with those with nonindolent SM, life expectancy in ISM was superior and not significantly different from that of the age- and sex-matched US population. In addition, multivariable analysis identified advanced age, weight loss, anemia, thrombocytopenia, hypoalbuminemia, and excess bone marrow blasts as independent adverse prognostic factors for survival. The current study validates the prognostic relevance of the WHO subclassification of SM and provides additional information of value in terms of both risk stratification and interpretation of clinical presentation and laboratory results.

Abstract Among 2333 consecutive patients with myelofibrosis with myeloid metaplasia (MMM) seen at our institution, 91 fulfilled the World Health Organization (WHO) criteria for leukemic transformation (LT). All episodes of LT were myeloid in origin (acute myeloid leukemia [AML]) with all French-American-British (FAB) subtypes represented except M3; the most frequent subtypes were M7 (25.4%), M0 (22.4%), and M2 (17.9%). Cytogenetic studies during LT were available in 56 patients and revealed a clonal abnormality in 51 (91%): 30 patients had complex karyotype, 2 had core-binding factor gene lesions, and 18 had abnormalities of chromosome 5 or 7. Karyotypic evolution was documented in the majority of the patients in whom serial analysis was possible. In general, LT was fatal in 98% of the cases after a median of 2.6 months (range, 0-24.2 months). Twenty-four patients received AML-like induction chemotherapy that resulted in no complete remission: 41% reverted into chronic-phase disease and the incidence of treatment-related mortality was 33%. The remaining 67 patients received either supportive care alone (48 patients) or low-intensity chemotherapy (19 patients). Overall, survival was similarly poor in all 3 treatment categories. The outcome of LT in MMM with current therapies is dismal and either supportive care alone or appropriate clinical trials should be considered.

Abstract A novel oncogenic mutation (FIP1L1-PDGFRA), which results in a constitutively activated platelet-derived growth factor receptor-α (PDGFRA), has been invariably associated with a primary eosinophilic disorder. The current study examines both the prevalence and the associated clinicopathologic features of this mutation in a cohort of 89 adult patients presenting with an absolute eosinophil count (AEC) of higher than 1.5 × 109/L. A fluorescence in situ hybridization (FISH)–based strategy was used to detect FIP1L1-PDGFRA in bone marrow cells. None of 8 patients with reactive eosinophilia displayed the abnormality, whereas the incidence of FIP1L1-PDGFRA in the remaining 81 patients with primary eosinophilia was 14% (11 patients). None (0%) of 57 patients with the hypereosinophilic syndrome (HES) but 10 (56%) of 19 patients with systemic mast cell disease associated with eosinophilia (SMCD-eos) carried the specific mutation. The bone marrow mast cell infiltration pattern in FIP1L1-PDGFRA+ SMCD-eos was distinctly diffuse with loose tumoral aggregates. Treatment with low-dose imatinib (100 mg/d) produced complete and durable responses in all 8 FIP1L1-PDGFRA+ cases treated. In contrast, only 40% partial response rate was seen in 10 HES cases. FIP1L1-PDGFRA is a relatively infrequent but treatment-relevant mutation in primary eosinophilia that is indicative of an underlying systemic mastocytosis.