Cerquozzi, Sonia

Abstract Introduction: Hypocellular myelodysplastic syndrome (h-MDS) represents only a small portion of MDS, of which, the clinical significance and outcomes are not well understood. Both laboratory and clinical evidence suggests that h-MDS shares immune-mediated pathogenic mechanisms similar to acquired aplastic anemia. As a result, immunosuppressive therapy (IST) has been the mainstay treatment. Since h-MDS is poorly understood and reported response rates to IST vary, we retrospectively reviewed the outcome of our patients with hypocellular MDS and identified the effectiveness of alternative therapy using hypomethylating agents (HMA). Methods: AllMDS patients over a 13-year period (June 1997 to May 2010) were captured after an IRB approval was obtained. Patients' demographics, labs, bone marrow aspirates and biopsies as well as cytogenetic data were collected. We used the currently accepted age-adjusted criteria to define hypocellularity as ≤ 30% in patients <70 years old, and ≤20% in >70 years old. Only patients with available response data were included in the final analysis. Survival estimates were calculated using Kaplan-Meier curves. Results: We identified 65 (8%) h-MDS patients from a cohort of 827 adult MDS. Median age was 68 years (range, 20-90), with 69% males. The largest group of patients were RAEB-1 at 9 (14%) and RAEB-2 at 14 (22%) along with RCMD at 18 (28%) and 15 (23%) MDS-U, 2 (3%) MDS 5q, 4 (6%) RARS and 2 (3%) were considered atypical. Cytogenetic analysis was normal in 17 (26%) with 7 (11%) having trisomy 8, and 11 (16%) and 14 (22%) having abnormalities of chromosome 7 and 5, respectively. IPSS-R were very low, low, intermediate, high, and very high in 4%, 30%, 28%, 21% and 17%, respectively. Leukemic transformation (LT) occurred in 6 (9%). The 4 year overall survival and progression free survival was 35% and 34%, respectively. Median overall survival and progression free survival was 30.2 and 29.7 months, respectively. Nine out 65 h-MDS patients were treated with a HMA, azacitidine (4) or decitabine (5). The median age of patients was 71 years (range, 66-85) with 6 (66%) being males. The median cellularity of the diagnostic bone marrow was 15% with the majority of patients presenting with RAEB-1 (11%) and RAEB-2 (55%) classification and 2 (22%) cases of RCMD as well as 1 (11%) case of MDS with isolated 5q. Cytogenetic analysis was normal in 3 (33%). IPSS-R were low in 1 (11%), intermediate in 4 (44%), high in 1 (11%) and very high risk in 3 (33%). The median time to initiation of a HMA from diagnosis was 5 months with response assessed at a median of 4.2 months. Two patients had received prior therapy including lenalidomide (for MDS 5q) and one had 1 cycle of trial therapy. Two patients (22%) achieved a marrow complete remission at a median time of 2.95 months; with one case of relapse at 9.8 months using HMA. Three patients (33%) had LT at a median time of 7.9 months post initiation of HMA. Median overall survival of patients with LT was 20 days. A total of 4 (44%) patients remain alive with a leukemia free survival of 67% at 2 years. In comparing to h-MDS patients without HMA treatment versus HMA treated, median OS was 28.2 vs 50.9 months (p=0.41) and PFS was 28.1 vs 40.6 months (p=0.69), respectively. Conclusions: The results from our clinical experience confirm that hypocellular MDS is a rare variant and that it is distinct from normocellular/hypercellular MDS. Two thirds of h-MDS received HMA for the treatment of higher risk disease (RAEB1-2). HMA has some efficacy in h-MDS. Further studies are warranted to better understand the clinical significance and outcomes of hypocellular MDS. Disclosures Binder: American Society of Hematology: Research Funding. Al-Kali:Celgene: Research Funding.

AbstractMonocytosis (absolute monocyte count, AMC ≥ 1 × 109/L) might accompany a spectrum of myeloid neoplasms, other than chronic myelomonocytic leukemia (CMML). In the current study, we examined the prevalence, laboratory and molecular correlates, and prognostic relevance of monocytosis in polycythemia vera (PV). Among 267 consecutive patients with World Health Organization (WHO)‐defined PV, 55 (21%) patients displayed an AMC of ≥1 × 109/L and 18 (7%) an AMC of ≥1.5 × 109/L. In general, PV patients with monocytosis were significantly older and displayed higher frequencies of leukocytosis (81% vs. 50% at AMC ≥1 × 109/L) and TET2/SRSF2 mutations (57%/29% vs. 19%/1% at AMC ≥ 1.5 × 109/L). In univariate analysis, AMC ≥1.5 × 109/L adversely affected overall (OS; P = .004; HR 2.6, 95% CI 1.4‐4.8) and myelofibrosis‐free (MFFS; P = .02; HR 4.4, 95% CI 1.3‐15.1) survival; during multivariable analysis, significance was borderline sustained for OS (P = .05) and MFFS (P = .06). Other independent risk factors for OS included unfavorable karyotype (P = .02, HR 3.39, 95% CI 1.17‐9.79), older age (P < .0001, HR 3.34 95% CI 1.97‐5.65), and leukocytosis ≥15 × 109/L (P = .004, HR 2.04, 95% CI 1.26‐3.29). In conclusion, in the current study, we encountered a higher than expected prevalence of monocytosis in patients with PV and the mutation profile and age distribution of PV patients with monocytosis is akin to those of patients with CMML and might partly contribute to their worse prognosis.

Myelofibrosis is a myeloproliferative neoplasm with cardinal features of extramedullary hematopoiesis, hepatosplenomegaly, cytopenias, and constitutional symptoms that result in shortened survival and leukemic transformation. It is a disease predominantly of the elderly, and currently available therapies only offer symptom control without curative benefit or ability to alter disease progression. Allogeneic hematopoietic stem-cell transplant (HSCT) is the only potentially curative intervention; however, this is only feasible in younger and medically fit patients and selectively offered to those with high-risk disease. Despite ongoing advancements, HSCT is associated with substantial morbidity and mortality, and the determination of which patients with myelofibrosis are ideal candidates and the selection of the opportune moment to proceed with transplantation remains challenging. This review summarizes our current recommendations for the role of and indications for HSCT in myelofibrosis.