Citations

BACKGROUNDThe 1996 National Cancer Institute Working Group (NCI‐WG 96) guidelines classified disease in individuals who had a B‐cell clone with chronic lymphocytic leukemia (CLL) immunophenotype as CLL if their absolute lymphocyte count was ≥5 × 109/L. The 2008 International Workshop on CLL guidelines (IWCLL 2008) classified disease as CLL if the absolute B‐cell count was ≥5 × 109/L or as monoclonal B‐cell lymphocytosis (MBL) if the absolute B‐cell count was <5 × 109/L. The objective of the current study of Olmsted County, Minnesota, was to assess the effects of these changes on incidence rates and presentation from 2000 to 2010.METHODSUsing diagnostic indices available through the Rochester Epidemiology Project and the Mayo CLL database, the authors identified all patients with newly diagnosed CLL and high‐count MBL from 2000 to 2010. Age‐specific and sex‐specific incidence rates were determined.RESULTSAccording to NCI‐WG 96 criteria, there were 115 patients with CLL and 8 patients with MBL during the period studied. Using the IWCLL 2008 classification, there were 79 patients with CLL and 40 patients with MBL. Rai stage distribution (low risk, intermediate risk, and high risk) using NCI‐WG 96 criteria was 60.9%, 33.9%, and 5.2%, respectively, compared with 43%, 49.4%, and 7.6%, respectively, using IWCLL 2008 criteria. The age‐adjusted and sex‐adjusted incidence rates (per 100,000) for CLL and MBL were 10.0 and 0.66, respectively, using NCI‐WG 96 criteria versus 6.8 and 3.5, respectively, using IWCLL 2008 criteria. The median time to treatment according to NCI‐WG 96 criteria was 9.2 years versus 6.5 years with IWCLL 2008 criteria.CONCLUSIONSUse of the IWCLL 2008 guidelines reduced the incidence of CLL, altered the distribution of initial Rai stage at diagnosis, and shortened the median time to treatment. Cancer 2014;120:2000–2005. © 2014 American Cancer Society.

SummaryChronic myelomonocytic leukaemia (CMML) is a clonal haematopoietic stem cell disorder with myelodysplastic and myeloproliferative overlap features, and an inherent tendency to transform to acute myeloid leukaemia. Approximately 30% of patients present with clonal cytogenetic abnormalities, while almost 90% have molecular aberrations involving epigenetic regulation, the spliceosome component machinery, tumour suppressor genes and transcription factors/regulators. Numerous prognostic models exist for CMML, with more recent models incorporating prognostic mutations, such as those involving ASXL1. Other variables that seem to consistently affect outcomes include the degree of leucocytosis/monocytosis, anaemia and thrombocytopenia. Allogeneic stem cell transplant remains the only curative option for CMML, while hypomethylating agents can be used for transplant‐ineligible patients or those without suitable stem cell sources. Targeting biological pathways activated in CMML offers potential hope for more effective and less toxic therapies.

Clonal eosinophilic disorders are rare among hematological malignancies. Most eosinophilia tends to be due to secondary causes such as infections, hypersensitivity conditions, drug reactions, and connective tissue disorders. The presence of a primary clonal eosinophilic disorder such as chronic eosinophilic leukemia—not otherwise specified (NOS) in the presence of a synchronous large cell lymphoma—is rare making the diagnosis challenging. We present a case of a 51-year-old female with the aforementioned presentation and demonstrate the extensive workup performed to identify the diagnosis.

Flow cytometry and other technologies of cell‐based fluorescence assays are as a matter of good laboratory practice required to validate all assays, which when in clinical practice may pass through regulatory review processes using criteria often defined with a soluble analyte in plasma or serum samples in mind. Recently the U.S. Food and Drug Administration (FDA) has entered into a public dialogue in the U.S. regarding their regulatory interest in laboratory developed tests (LDTs) or so‐called home brew assays performed in clinical laboratories. The absence of well‐defined guidelines for validation of cell‐based assays using fluorescence detection has thus become a subject of concern for the International Council for Standardization of Haematology (ICSH) and International Clinical Cytometry Society (ICCS). Accordingly, a group of over 40 international experts in the areas of test development, test validation, and clinical practice of a variety of assay types using flow cytometry and/or morphologic image analysis were invited to develop a set of practical guidelines useful to in vitro diagnostic (IVD) innovators, clinical laboratories, regulatory scientists, and laboratory inspectors. The focus of the group was restricted to fluorescence reporter reagents, although some common principles are shared by immunohistochemistry or immunocytochemistry techniques and noted where appropriate. The work product of this two year effort is the content of this special issue of this journal, which is published as 5 separate articles, this being Validation of Cell‐based Fluorescence Assays: Practice Guidelines from the ICSH and ICCS ‐ Part IV ‐ Postanalytic considerations. © 2013 International Clinical Cytometry Society

BACKGROUNDAlthough rituximab‐based chemoimmunotherapy (CIT) has substantially improved clinical outcomes in chronic lymphocytic leukemia (CLL), only 40% to 50% of patients achieve a complete remission (CR). There remains interest in identifying new approaches to improve the effectiveness of CIT. Ofatumumab is a fully human anti‐CD20 monoclonal antibody with greater apparent single‐agent activity than rituximab in CLL patients.METHODSPreviously untreated CLL patients in need of therapy received 6 cycles of CIT induction with pentostatin, cyclophosphamide, and ofatumumab (PCO) followed by response assessment.RESULTSOf the 48 patients enrolled, 77% completed PCO induction. Adverse events during induction included grade 3+ hematologic toxicity (27%) and grade 3+ nonhematologic toxicity (23%). Median CD4 count after induction and 6 months later were 186 × 106/L and 272 × 106/L. The overall response rate was 96% (46 of 48 patients), and the CR rate was 46% (22 of 48 patients). Among the 38 patients who underwent minimal residual disease evaluation, 7 (18%) were negative for minimal residual disease. After median follow‐up of 24 months, 10 (21%) patients have progressed and 8 (17%) have required retreatment. The efficacy and toxicity of ofatumumab‐based CIT compare favorably to our historical trials of rituximab‐based CIT using an identical chemotherapy backbone (n = 64). Time to retreatment also appeared longer for ofatumumab‐based CIT (free of retreatment at 24 months: 86% [95% confidence interval = 75‐99] versus 68% [95% confidence interval = 56‐81] for rituximab‐based CIT).CONCLUSIONSOfatumumab‐based CIT is well tolerated in patients with previously untreated CLL. The efficacy of ofatumumab‐based CIT compares favorably to historical trials of rituximab‐based CIT, suggesting randomized trials comparing ofatumumab‐based CIT and rituximab‐based CIT should be considered. Cancer 2013;119:3788–3796. © 2013 American Cancer Society.

SummaryNearly all information about patients with chronic lymphocytic leukaemia (CLL) who develop diffuse large B‐cell lymphoma [Richter syndrome (RS)] is derived from retrospective case series or patients treated on clinical trials. We used the Mayo Clinic CLL Database to identify patients with newly diagnosed CLL between January 2000 and July 2011. Individuals who developed biopsy‐proven RS during follow‐up were identified. After a median follow‐up of 4 years, 37/1641 (2·3%) CLL patients developed RS. The rate of RS was approximately 0·5%/year. Risk of RS was associated with advanced Rai stage at diagnosis (P < 0·001), high‐risk genetic abnormalitites on fluorescence in situ hybridization (P < 0·0001), unmutated IGHV (P = 0·003), and expression of ZAP70 (P = 0·02) and CD38 (P = 0·001). The rate of RS doubled in patients after treatment for CLL (1%/year). Stereotyped B‐cell receptors (odds‐ratio = 4·2; P = 0·01) but not IGHV4‐39 family usage was associated with increased risk of RS. Treatment with combination of purine analogues and alkylating agents increased the risk of RS three‐fold (odds‐ratio = 3·26, P = 0·0003). Median survival after RS diagnosis was 2·1 years. The RS prognosis score stratified patients into three risk groups with median survivals of 0·5 years, 2·1 years and not reached. Both underlying characteristics of the CLL clone and subsequent CLL therapy influence the risk of RS. Survival after RS remains poor and new therapies are needed.

Cytogenetic classification by the revised international prognostic scoring system (IPSS‐R) and the prognostic value of monosomal karyotype (MK) were assessed in 783 patients with primary myelodysplastic syndromes (MDS). At 22 months median follow‐up, 562 (72%) deaths were recorded. Percentages of patients with IPSS‐R “very good,” “good,” “intermediate,” “poor,” and “very poor” cytogenetic categories was 5, 63, 18, 4, and 10%, respectively. The corresponding median survivals were 21, 40, 24, 18, and 6.5 months and the inter‐group differences (good vs. very good/intermediate/poor vs. very poor; P < 0.01) or similarities (very good vs. intermediate vs. poor; P = 0.79) were not significantly modified in multivariable analysis. Results were similar when analysis was restricted to 602 patients managed by supportive care. MK adversely affected survival in both poor and very poor karyotype groups (P < 0.01). In conclusion, we were unable to confirm the prognostic superiority of IPSS‐R‐very good karyotype or prognostically distinguish between very good, intermediate and poor karyotypes. Furthermore, we show additional prognostic information from MK in poor/very poor karyotype. Am. J. Hematol. 88:690–693, 2013. © 2013 Wiley Periodicals, Inc.

Key Points Lenalidomide consolidation repairs T-cell immune synapses in CLL patients. Lenalidomide consolidation improved the quality of response in CLL patients treated with chemoimmunotherapy.

SRSF2, SF3B1, and U2AF35 (U2AF1) are the three most frequent genes involved with spliceosome mutations in myeloid malignancies. SF3B1 mutations are most frequent (~80%) in myelodysplastic syndromes (MDS) with ring sideroblasts (RS) but lack prognostic relevance. SRSF2 mutations are associated with shortened overall (OS) and leukemia‐free survival (LFS) in both MDS and myelofibrosis. In this study of 226 patients with chronic myelomonocytic leukemia (CMML), mutational frequencies were 40% for SRSF2 (all affecting P95), 6% for SF3B1 (primarily K700E) and 9% for U2AF35 (mostly S34F and Q157P/R). These mutations were mutually exclusive and 54% of the patients displayed at least one mutation. The three mutation groups were phenotypically similar, with the exception of higher RS% (P < 0.0001) in patients with SF3B1 mutations. At a median follow‐up of 15 months, 176 (78%) deaths and 32 (14%) leukemic transformations were documented. OS (median survivals of 17, 16, 17, and 20 months; P = 0.48) and LFS (leukemic transformation rates of 17, 13, 15, and 5%; P = 0.63) were similar among patients with none of the three mutations, SRSF2, SF3B1, or U2AF35 mutations, respectively. We conclude that SRSF2 is the most frequently mutated spliceosome gene in CMML but neither it nor SF3B1 or U2AF35 mutations are prognostically relevant. Am. J. Hematol. 88:201–206, 2013. © 2012 Wiley Periodicals, Inc.

Abstract Among spliceosome component mutations, those involving SF3B1 are most frequent in myelodysplastic syndromes with ring sideroblasts (MDS-RS; ∼ 75% incidence) and SRSF2 in chronic myelomonocytic leukemia (∼ 28% incidence). We recently reported on the lack of prognostic significance for SF3B1 mutations in both MDS-RS and primary myelofibrosis (PMF). In the current study, we examined the prevalence and prognostic relevance of SRSF2 mutations in PMF. Among 187 patients screened, 32 (17%) harbored SRSF2 monoallelic mutations affecting residue P95. Significant associations were demonstrated between SRSF2 mutations and advanced age (P < .01), IDH mutations (P < .01), and higher DIPSS-plus risk category (P = .03). SRSF2 mutations were associated with shortened overall (P < .01) and leukemia-free (P < .01) survival; the adverse effect on survival was independent of DIPSS-plus (P = .01; HR = 1.9; 95% CI, 1.1-3.0) and IDH mutations (P < .01; HR = 2.3; 95% CI, 1.4-3.8). In conclusion, SRSF2 mutations are relatively common in PMF, cluster with IDH mutations, and are independently predictive of poor outcome.