Citations

Abstract Introduction: Surveillance, Epidemiology, and End Results (SEER) registry captures data on acute leukemias (AL) that morphologically do not conform to well characterized acute leukemic entities in the established French-American-British (FAB) nomenclature. Not much is known about population level outcomes of these rare AL. We performed a comprehensive survival analysis of these rare AL over a forty-year period using the SEER registry. Methods: SEER 18 dataset was queried to identify adult patients (pts > 18 years) diagnosed with Acute Myeloid Leukemia (AML), Acute Lymphoblastic Leukemia (ALL) and rare AL from 1973-2012. Rare AL cases were identified using ICD-O-3 morphology codes and included Leukemias, Not Otherwise Specified (NOS) (9800-01, 9860) and myeloid sarcoma (9930). Data on demographics,follow up and survival was abstracted. Univariate and multivariate analysis was performed to identify factors influencing survival of rare AL and survival patterns were compared to AML and ALL. Hazard ratios (HR) with 95% confidence intervals (CIs) are reported. Results: We identified 61,550 AML pts, 13,457 ALL pts, 525 myeloid sarcoma pts and 13,446 pts with leukemia NOS. Median age at diagnosis was 68 years (yrs, range 18-100) for AML, 54 yrs (18-100) for ALL, 65 yrs (18-95) for myeloid sarcoma and 76 yrs (18-100) for leukemia NOS. Gender distribution was similar with females comprising 45.9% of AML, 43% of ALL, 42.3% of myeloid sarcoma and 47.2% of leukemia NOS cases. Over 80% pts in all categories were Caucasian. Median survival was as follows: 0.4 (0-40) yrs for AML; 1.4 (0-39.8) yrs for ALL; 0.7 (0-32.9) yrs for Myeloid Sarcoma; and 0.3 (0-38.9) yrs for leukemia NOS. In univariable analysis, younger age predicted for better survival for both myeloid sarcoma and leukemia NOS (p<0.0001). Improvement in survival over time period was observed for pts with leukemia NOS (p < 0.0001). In multivariable analysis, advancing age was an independent prognostic factor for rare AL, both as a continuous variable and when categorized as older vs. younger pts using age cutoff of 60 yrs. Compared to younger pts, HR for pts > 60 yrs with rare AL was as follows: 2.68 (2.13-3.37; p <0.0001) for myeloid sarcoma; and 2.18 (2.07-2.31; p<0.0001) for leukemia NOS. No difference in survival over time was seen for myeloid sarcoma. Pts with leukemia, NOS diagnosed in yrs 2006-2012 (HR=0.87; 0.82-0.92; p < 0.0001) had better survival compared to the referent years 1973-80. Race and gender did not impact survival. In multivariable analysis, pts with leukemia NOS did worse overall compared to AML (HR=1.13; 1.11-1.53; p<0.0001) and ALL (HR=1.86; 1.81-1.91; p<0.0001). Interestingly, younger pts had a poorer outcome than AML (HR=1.10; 1.04-1.16; p=0.0003), but pts > 60 yrs had a better outcome (HR=0.93; 0.91-0.95; p<0.0001). Both younger (HR=1.33; 1.26-1.41; p<0.0001) and older pts (HR=1.45, 1.40-1.50: p<0.0001) compared unfavorably to ALL (Figure 1). Pts with myeloid sarcoma had a better survival compared to AML pts (HR=0.77; 0.7-0.85; p<0.0001) (Figure 2). This was uniform for pts <60 yrs (HR=0.77; 0.64-0.93; p=0.006) and > 60 yrs (HR= 0.77; 0.69-0.87; p<0.0001). Conclusion: Pts with leukemias NOS have poor outcomes compared to AML and ALL but prognosis has improved in recent years. The most probable explanation is identification of prognostic molecular mutations that has allowed accurate risk-stratification of pts using the WHO classification and in turn better selection of treatment strategies. Several reasons have limited our understanding of these rare AL - small numbers, exclusion from clinical trials and wide variability in treatment options used. Efforts at better molecular characterization of these AL holds the most promise for improving outcomes. Disclosures Sekeres: Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; TetraLogic: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees.

Purpose To investigate the risk and outcomes of second hematologic malignancies (SHMs) in a population-based cohort of patients with well-differentiated thyroid cancer (WDTC) treated or not with radioactive iodine (RAI). Methods Patients with WDTC were identified from SEER registries. Competing risk regression analysis was performed to calculate the risks of SHMs that occurred after WDTC treatment and outcomes after SHM development were assessed. Results Of 148,215 patients with WDTC, 53% received surgery alone and 47% received RAI. In total, 783 patients developed an SHM after a median interval of 6.5 years (interquartile range, 3.3 to 11.2 years) from WDTC diagnosis. In multivariable analysis, compared with those undergoing thyroidectomy alone, RAI treatment was associated with an increased early risk of developing acute myeloid leukemia (AML; hazard ratio, 1.79; 95% CI, 1.13 to 2.82; P = .01) and chronic myeloid leukemia (CML; hazard ratio, 3.44; 95% CI, 1.87 to 6.36; P < .001). This increased risk of AML and CML after RAI treatment was seen even in low-risk and intermediate-risk WDTC tumors. Occurrence of AML but not CML in patients with WDTC was associated with shorter median overall survival compared with matched controls (8.0 years v 31.0 years; P = .001). In addition, AML developing after RAI trended toward inferior survival compared with matched controls with de novo AML (median overall survival, 1.2 years v 2.9 years; P = .06). Conclusion Patients with WDTC treated with RAI had an increased early risk of developing AML and CML but no other hematologic malignancies. AML that arises after RAI treatment has a poor prognosis. RAI use in patients with WDTC should be limited to patients with high-risk disease features, and patients with WDTC treated with adjuvant RAI should be monitored for myeloid malignancies as part of cancer surveillance.

Abstract Myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN) are hematologically diverse stem cell malignancies sharing phenotypic features of both myelodysplastic syndromes and myeloproliferative neoplasms. There are currently no standard treatment recommendations for most adult patients with MDS/MPN. To optimize efforts to improve the management and disease outcomes, it is essential to identify meaningful clinical and biologic end points and standardized response criteria for clinical trials. The dual dysplastic and proliferative features in these stem cell malignancies define their uniqueness and challenges. We propose response assessment guidelines to harmonize future clinical trials with the principal objective of establishing suitable treatment algorithms. An international panel comprising laboratory and clinical experts in MDS/MPN was established involving 3 independent academic MDS/MPN workshops (March 2013, December 2013, and June 2014). These recommendations are the result of this collaborative project sponsored by the MDS Foundation.

Abstract Even though mutations in epigenetic regulators frequently occur in myeloproliferative neoplasms, their effects on the epigenome have not been well studied. Furthermore, even though primary myelofibrosis (PMF) has a markedly worse prognosis than essential thrombocytosis or polycythemia vera, the molecular distinctions between these subgroups are not well elucidated. We conducted the HELP (HpaII tiny fragment enriched by LM-PCR) assay to study genome-wide methylation in polycythemia vera, essential thrombocytosis, and PMF samples compared with healthy controls. We determined that polycythemia vera and essential thrombocytosis are characterized by aberrant promoter hypermethylation, whereas PMF is an epigenetically distinct subgroup characterized by both aberrant hyper- and hypomethylation. Aberrant hypomethylation in PMF was seen to occur in non-CpG island loci, showing further qualitative differences between the disease subgroups. The differentially methylated genes in polycythemia vera and essential thrombocytosis were involved predominantly in cell signaling pathways and were enriched for binding sites of GATA1 and other transcription factors. In contrast, aberrantly methylated genes in PMF were involved in inflammatory pathways and were enriched for NF1, LEF1, and other transcription factors. Within the PMF subgroup, cases with ASXL1 disruptions formed an epigenetically distinct subgroup with relatively increased methylation. Cases of myeloproliferative neoplasms (MPN) with TET2 mutations showed decreased levels of hydroxymethylation and distinct set of hypermethylated genes. In contrast, the JAK2V617F mutation did not drive epigenetic clustering within MPNs. Finally, the significance of aberrant methylation was shown by sensitivity of MPN-derived cell lines to decitabine. These results show epigenetic differences between PMF and polycythemia vera/essential thrombocytosis and reveal methylomic signatures of ASXL1 and TET2 mutations. Cancer Res; 73(3); 1076–85. ©2012 AACR.

Lenalidomide is the first karyotype-selective therapeutic approved for the treatment of myelodysplastic syndromes (MDS) owing to high rates of erythroid and cytogenetic response in patients with chromosome 5q deletion [del(5q)]. Although haploinsufficiency for the RPS14 gene and others encoded within the common deleted region (CDR) have been implicated in the pathogenesis of the del(5q) phenotype, the molecular basis of the karyotype specificity of lenalidomide remains unexplained. We focused our analysis on possible haplodeficient enzymatic targets encoded within the CDR that play key roles in cell-cycle regulation. We show that the dual specificity phosphatases, Cdc25C and PP2Acα, which are coregulators of the G 2 -M checkpoint, are inhibited by lenalidomide. Gene expression was lower in MDS and acute myeloid leukemia (AML) specimens with del(5q) compared with those with alternate karyotypes. Lenalidomide inhibited phosphatase activity either directly (Cdc25C) or indirectly (PP2A) with corresponding retention of inhibitory phospho-tyrosine residues. Treatment of del(5q) AML cells with lenalidomide induced G 2 arrest and apoptosis, whereas there was no effect in nondel(5q) AML cells. Small interfering RNA (shRNA) suppression of Cdc25C and PP2Ac α gene expression recapitulated del(5q) susceptibility to lenalidomide with induction of G 2 arrest and apoptosis in both U937 and primary nondel(5q) MDS cells. These data establish a role for allelic haplodeficiency of the lenalidomide inhibitable Cdc25C and PP2Acα phosphatases in the selective drug sensitivity of del(5q) MDS.