Ketterling, Rhett P.

AbstractPalliative treatment in myelofibrosis (MF) includes transfusion support, JAK2 inhibitors, involved field radiotherapy and splenectomy. To assist in selecting patients who are likely to benefit from splenectomy, we looked into risk factors for postsplenectomy survival, in 120 consecutive cases (median age 66 years); at the time of splenectomy, 61% displayed red cell transfusion need, 49% platelet count <100 × 10(9)/L, 25% leukocyte count >25 × 10(9)/L, 60% constitutional symptoms and 13% circulating blasts ≥5%; dynamic international prognostic scoring system risk categories were 21% high, 55% intermediate‐2, 21% intermediate‐1 and 3% low. Among informative cases, karyotype was abnormal in 60% and driver mutational status was JAK2 75%, CALR 15%, MPL 4% and triple‐negative 6%. At median follow‐up of 1.3 years, from time of splenectomy, 95 (79%) deaths and 30 (25%) leukemic transformations were recorded. Median postsplenectomy survival was 1.5 years; in multivariable analysis, survival was adversely affected by age >65 years, transfusion need, leukocyte count >25 × 10(9)/L and circulating blasts ≥5%; these variables were subsequently used to devise an HR‐weighted scoring system with high (3‐4 risk factors), intermediate (2 risk factors) and low (0‐1 risk factors) risk categories; the corresponding postsplenectomy median survivals were 0.3 (HR 5.9, 95% CI 3.2‐11.0), 1.3 (HR 2.9, 95% CI 1.8‐4.6) and 2.9 years. Postsplenectomy survival was not affected by driver mutational status or occurrence of leukemic transformation. Leukemia‐free survival was predicted by very high risk karyotype. The observations from the current study might help identify appropriate candidates for splenectomy in MF.

Objective We observed that pediatric patients with B lymphoblastic leukemia which expressed CD36 at diagnosis seemed to have worse outcome than patients whose blasts did not. Here, we describe the patient, disease characteristics, pathological, molecular, and genetic features and outcomes of patients with CD36+ B-LL compared to patients with CD36− B-LL. Methods We retrospectively reviewed all flow cytometry reports from September 2008 to December 2015 to identify patients diagnosed at our institution with CD36 expression on B lymphoblasts. CD36− control patients were chosen from our leukemia database and matched 2:1 to CD36+ patients for National Cancer Institute (NCI) risk group at diagnosis. We reviewed diagnostic marrow slides for cytoplasmic granules and abstracted clinical data from patient charts. To identify underlying genetic abnormalities, clinical FISH testing and RNA sequencing was performed on 5 of our CD36+ patients, and RNA-seq data from the NIH Therapeutically Applicable Research to Generate Effective Treatments (TARGET) ALL Expansion Phase 2 data set were examined. Results Twenty-five of 366 (6.83%) patients diagnosed at our institution in the study period had CD36+ blasts. With a median follow-up of 5.32 years, 5-year event-free survival (EFS) and overall survival (OS) were significantly worse for CD36+ patients compared to CD36− patients who were NCI Standard Risk at diagnosis (EFS: 60% ± 15.49 vs 95% ± 4.87, P = .016; OS: 90% ± 9.5 vs 100%, P = .019). NCI Standard Risk patients whose blasts were both CD36+ and had granules had the worst survival compared to CD36− patients without granules (EFS 25% ± 21.65 vs 95% ± 4.87, P = .0004). From our CD36+ patients and the TARGET database, we found 2 ABL2 mutations, 1 PDGFRB mutation, and 2 NRAS mutations. Conclusions For NCI Standard Risk patients, CD36 expression on B-lymphoblasts identifies patients with B-LL who have especially poor outcome. This may be due to underlying genetic abnormalities that may be amenable to targeted therapy.

SummaryThe definition of the myelodysplastic syndrome (MDS) subtype ‘MDS with isolated del(5q)’ was expanded to include cases with one additional non‐chromosome 7 based cytogenetic abnormality in the 2016 revised World Health Organization classification. This study applied the revised definition to a large primary MDS cohort, and evaluated the prognostic impact of the additional cytogenetic abnormality. Seventy‐two of 1067 patients (7%) met the ‘MDS with isolated del(5q)’ criteria, 11 (1%) of whom had an additional cytogenetic abnormality. There was no survival difference between patients in whom del(5q) occurred alone, compared to those with one additional cytogenetic abnormality (P = 0·52).

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.

AbstractAtypical chronic myeloid leukemia (aCML) is an aggressive myeloid neoplasm with overlapping features of myelodysplastic syndromes (prominent granulocytic dysplasia) and myeloproliferative neoplasms (neutrophilic leukocytosis). We studied 25 molecularly‐annotated and World Health Organization defined aCML patients; median age 70 years, 84% males. Cytogenetic abnormalities were seen in 36% and gene mutations in 100%. Mutational frequencies were, ASXL1 28%, TET2 16%, NRAS 16%, SETBP1 12%, RUNX1 12%, ETNK1 8%, and PTPN11 4%. Fifteen patients (60%) had >1 mutation, while 9 (36%) had ≥3. The median overall survival (OS) was 10.8 months and at last follow up (median 11 months), 17 (68%) deaths and 2 (8%) leukemic transformations were documented. On univariate analysis, survival was adversely impacted by advanced age (P = .02), low hemoglobin (P = .01), red blood cell transfusion dependence (P = .03), high white blood cell count (P = .02), TET2 (P = .03), NRAS (P = .04), PTPN11 (P = .02) mutations and the presence of ≥3 gene mutations (P = .006); ASXL1, SETBP1, and ETNK1 mutations did not impact OS. In multivariable analysis, advanced age (P = .003) [age >67: HR 10.1, 95% CI 1.3‐119], low hemoglobin (P = .008) [HB< 10 gm/dL: HR 8.2, 95% CI 1.6‐23.2] and TET2 mutations (P = .01) [HR 8.8, 95% CI 1.6‐47.7] retained prognostic significance. We then used age >67 years, hemoglobin <10 gm/dL and the presence of TET2 mutations (each counted as one risk factor) to create a hazard ratio weighted prognostic model; effectively stratifying patients into two risk categories, low (0‐1 risk factor) and high (≥2 risk factors), with median OS of 18 and 7 months, respectively.

AbstractCytogenetics can inform risk stratification in pediatric acute myeloid leukemia (AML). We describe the first case of a newborn with leukemia cutis found to have AML harboring a cryptic insertional t(8;16)(p11.2;p13.3) with associated KAT6A/CREBBP fusion identified exclusively by fluorescence in situ hybridization (FISH). Expectant management resulted in spontaneous leukemia resolution. The identification of t(8;16)(p11.2;p13.3) may serve as a biomarker for spontaneous remission in congenital AML. FISH for this translocation is warranted in congenital AML with a normal karyotype, and patients with KAT6A/CREBBP fusion should be conservatively managed. While 50% of spontaneously remitting congenital AML with t(8;16)(p11.2;p13.3) may recur, high salvage rates are attained with standard therapy.