Raza, Sania S.

Abstract Abstract 3840 Background: Patients with myeloproliferative neoplasms (MPN) harbor a multitude of somatic mutations involving JAK2, MPL, LNK, CBL, TET2, ASXL1, IDH1, IDH2, EZH2, DNMT3A, IKZF1 and TP53. None of these mutations have been consistently traced back to the ancestral clone and most of them are currently believed to represent secondary genetic events. The higher prevalence of IDH, LNK, IKZF1 and TP53 mutations in blast-phase MPN, as opposed to chronic-phase disease, suggests their pathogenetic contribution to leukemic transformation (Harutyunyan A, et al. N Engl J Med. 2011;364:488). We examined this possibility for TP53 mutations or its SNPs in chronic-phase PMF; TP53 SNPs involving codon 72 have been associated with increased risk in the development of several cancers. Methods: Mayo Clinic MPN database was utilized to identify adult patients (>18 years) with chronic-phase PMF. Study eligibility criteria included availability of bone marrow histology and cytogenetic information at time of referral. In addition, all patients were annotated for IDH, MPL and JAK2 mutational status. Patients with blast-phase disease at the time of their referral were excluded from the study. DNA from bone marrow or peripheral blood was extracted using conventional methods and amplified with one set of primers covering TP53 exons 4 through 9. The amplification products were then sequenced with eight primers using the Big Dye Terminator sequencing kit v1.1 (Applied Biosystems, Foster City, CA) and the ABI 3130xl Genetic Analyzer. Sequences were examined for mutations by the Sequencher software (Gene Codes, Ann Arbor, MI). Any mutation found was confirmed with a second PCR and sequencing reaction. A mutation was considered to be any sequence other than genomic reference sequence NC_000017.10 or a well documented polymorphism such as the rs1042522 in exon 4. Mutations were compared with the IARC p53 Database (http://www-p53.iarc.fr/) and/or the TP53 Mutation Database (http://p53.free.fr/index.html) to determine if the mutation had been reported before. Results I: Baseline characteristics and clinical course A total of 107 patients with chronic-phase PMF were studied. Median age at time of referral was 64 years (range 32–81) and 71% were males. DIPPS-plus risk assignment was low in 13%, intermediate-1 in 15%, intermediate-2 in 38% and high in 34%. Karyotype was normal in 70 (65%) patients, favorable in 26 (24%) and unfavorable in 11 (10%). JAK2, MPL and IDH mutations were detected in 62 (58%), 7 (7%) and 6 (6%) cases, respectively. To date, 74% of patients had died and 15% had documented leukemic transformation. Results II: TP53 mutations/polymorphisms and their clinical relevance TP53 mutations were discovered in only 4 (4%) cases: i) E204E; GAG>GAA (silent exon 6); ii) G245D; GGC>GAC (exon 7); iii) R175H; CGC>CAC (exon 5); and iv) six base insert (GGCGAG) after bp13767 (exon 6). There was no significant difference in presenting features or survival between TP53 mutated and unmutated cases. None of the four patients with TP53 mutation incurred leukemic transformation. TP53 exon 4 SNPs data for codon 72 was available on 104 patients and included 58 (56%) patients with homozygous Arg72Arg, 34 (33%) patients with heterozygous Pro72Arg and 12 (11%) patients with homozygous Pro72Pro. Allele frequencies were 0.7 for G (corresponding to arginine) and 0.3 for C (corresponding to proline), which is similar to the general population (0.65 and 0.35 respectively). There were no significant differences among the three codon 72 genotypes in terms of presenting characteristics or survival. Conclusions: TP53 mutations are infrequent in chronic phase PMF. A higher number of informative cases are needed to accurately define their phenotypic or prognostic effects. We are currently analyzing more cases in this regard. On the other hand, TP53 polymorphisms at codon 72 do not appear to influence phenotype or prognosis in chronic-phase PMF. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 3850 Background: We have recently shown that primary myelofibrosis (PMF) was associated with increased plasma levels of IL-1b/IL-1RA/IL-2R/IL-6/IL-8/IL-10/IL-12/IL-13/IL-15/TNF-α/G-CSF/INF-α/MIP-1α/MIP-1b/HGF/IP-10/MIG/MCP-1/VEGF in PMF (J Clin Oncol 2011; 29: 1356). In addition, increased levels of IL-8, IL-2R, IL-12, IL-15 and IP-10 were independently associated with inferior survival. In the current study, we focused on the plasma cytokine profile in polycythemia vera (PV) and examined how it compares with PMF or in a cohort of PV patients whose samples were collected during follow-up. We also looked for phenotypic and prognostic correlates. Methods: Study inclusion for patients with PV required availability of archived plasma within one year of diagnosis. Samples from PV patients seen at different points post-diagnosis were also collected, in order to compare their cytokine profile with that of patients whose samples were collected within one year of diagnosis. Standard procedures were followed to centrifuge peripheral blood samples at 4°C and store aliquots at −80°C. Concentrations of 30 plasma cytokines/chemokines were analyzed in duplicates using Multiplex Bead-based Luminex Technology (Invitrogen, Carlsbad, CA, USA): IL-1β, IL-1RA, IL-2, IL-2R, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, EGF, eotaxin, FGF-b, GM-CSF, G-CSF, HGF, IFN-α, IFN-γ, IP-10, MCP-1, MIG, MIP-1α, MIP-1β, RANTES, TNF-α, and VEGF. Measurements were performed on a Luminex 200 analyzer (Luminex Corporation, Austin, TX, USA) and resulting data were evaluated using STarStation Software Version 2.3 (Luminex Corporation, Austin, TX, USA). Results I: Plasma cytokines in PV (n=36 for samples collected within one year of diagnosis and n=40 for samples collected beyond that time point) vs. PMF (n=92) vs. normal controls (n=35) There was no significant difference between the three groups in the plasma levels of the following cytokines: IL-1β, IL-2, IL-4, EGF, and IL-17. PV and normal controls had similar levels of IL-2R, IL-5, FGF-b, and TNF-α; all four cytokines were elevated in PMF. The levels of the following cytokines were equally increased in PV and PMF: IL-1RA, IL-7, HGF, MIG, and VEGF. The following cytokines were also elevated in both PMF and PV but predominantly so in PV (MIP-1α) or PMF (IL-6, IL-8, IL-12, IL-13, IL-15, MIP-1β, IP-10, and MCP-1). Eotaxin and GM-CSF were elevated in PV but not PMF. Compared to normal controls, significantly lower levels were noted for IL-10 in PV and IFN-α and IFN-γ for PMF. IFN-α and IFN-γ levels were both elevated in PV. Comparison of PV samples collected within one year of diagnosis (n =36) vs. those collected beyond that time point (n =40) showed significantly increased levels of IL-8 (p=0.0005) and borderline significant increases in IP-10 (p=0.09) and IL-2R (p=0.09). Results II: Clinical correlates of plasma cytokines in PV Among the above-listed cytokines that were abnormally increased or decreased in PV, significant correlations were seen with sex (IP-10 and GM-CSF), age (IP-10, eotaxin), platelet count (MIG), hemoglobin level (IL-6), arterial thrombosis (IFN-γ, IL-1RA, VEGF, MIP-1α), and abnormal karyotype (IL-13, MIP-1α). None of the cytokines correlated with leukocyte count, venous thrombosis, pruritus or microvascular symptoms. The following, treated as continuous variables, were associated with inferior survival: IL-7, HGF, IFN-α, MCP-1, GM-CSF and IL-10 (p<0.05 for all). The number of events and sample size were too small to perform multivariable analysis. Conclusions: Plasma cytokine levels in PV are markedly abnormal and show both similarities and differences with PMF; the similarities became more pronounced in patients whose samples were examined at later stages of their disease. The current study suggests prognostic implications that warrant validation in a larger number of patients. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 2705 Background: Due to similar cytomorphological features and treatment strategies, T lineage lymphomas (T-LBL) and lymphoblastic leukemias (T-ALL) are usually grouped together as a single entity. Traditionally, the difference between T-LBL and T-ALL has been based on percentage of blasts found in the bone marrow (BM): >25% BM blasts and/or presence of peripheral blood (PB) blasts consistent with T-ALL. Recent studies, based on immunophenotypic, cytogenetic and molecular differences, emphasize the clinical uniqueness between T-LBL and T-ALL and argue against grouping them as a single entity. Objectives: To perform a clinicopathologic and cytogenetic comparison between patients with T-LBL and T-ALL in order to identify differences between these disease groups. Methods: We utilized the Mayo Clinic Lymphoma database to identify consecutive adult patients (>18 years) diagnosed with T-cell leukemia and lymphoma from 1980 to 2010. The patients were sub-divided into T-LBL and T-ALL based on BM and PB blasts (absence of BM and PB blasts consistent with T-LBL). Clinicopathological and cytogenetic characteristics were retrospectively reviewed. Result: 50 patients met the criteria for T-cell leukemia/lymphoma (29-T-ALL, 21-T-LBL). 50% of patients in each group were females with median age at diagnosis of 32 years for T-LBL and 29 years for T-ALL. Characteristics associated with a statistically significant survival difference for the cohort included: white blood cell count at diagnosis (>100,000/cmm), platelet count (<50,000/cmm), LDH (>500 U/L), presence of BM blasts and an adverse karyotype (hypodiploidy and MLL rearrangements). ECOG performance status, number of lymph node groups involved, extranodal disease, CNS involvement and constitutional symptoms had no impact on survival. Furthermore, no overall survival difference between patients with T-LBL and T-ALL was identified (figure 1). Among patients with T-LBL, 11 (51%) patients with extranodal disease had shortened survival (p=0.02). CNS involvement was seen in 4 (19%) of T-LBL patients and 5 (17%) of T-ALL patients, and did not affect overall survival (p=0.8). 4 (19%) T-LBL patients and 1 (3%) T-ALL patient had pleural involvement at diagnosis. There were no morphologic, flow cytometric, or immunohistochemical differences noted between the two groups. Conclusion: In a large study from a single institution, we confirm no survival difference between T-LBL and T-ALL, which further provides ongoing support that from a therapeutic standpoint these groups can be viewed as a single entity. However, we hope to further clarify clinical differences by performing microarray and chemokine analysis on available tissue specimens. Disclosures: No relevant conflicts of interest to declare.