Luca Arcaini

Prognostic Factors and Life Expectancy in Myelodysplastic Syndromes Classified According to WHO Criteria: A Basis for Clinical Decision Making

PURPOSE The aim of this study was to evaluate the prognostic value of the WHO proposal, to assess the role of the main prognostic factors in myelodysplastic syndromes (MDSs) classified into WHO subgroups, and to estimate mortality (standardized mortality ratio [SMR]) and life expectancy in these groups as a basis for clinical decision making. PATIENTS AND METHODS Four hundred sixty-seven patients who were diagnosed as having de novo MDS at the Division of Hematology, University of Pavia (Pavia, Italy), between 1992 and 2002, were evaluated retrospectively for clinical and hematologic features at diagnosis, overall survival (OS), and progression to leukemia (leukemia-free survival). RESULTS Significant differences in survival were noted between patients with refractory anemia (RA), refractory cytopenia with multilineage dysplasia, RA with excess blasts, type 1 (RAEB-1), and RAEB-2. The effect of demographic factors on OS was observed in MDS patients without excess blasts (age, P = .001; sex, P = .006), as in the general population. The mortality of RA patients 70 years or older did not differ significantly from that of the general population (SMR, 1.62; P = .06). Cytogenetics was the only International Prognostic Scoring System variable showing a prognostic value in MDS classified into WHO subgroups. Transfusion-dependent patients had a significantly shorter survival than patients who did not require transfusions (P < .001). Developing a secondary iron overload significantly affected the survival of transfusion-dependent patients (P = .003). CONCLUSION These data show that the WHO classification of MDSs has a relevant prognostic value. This classification, along with cytogenetics, might be useful in decisions regarding transplantation. MDS with isolated erythroid lineage dysplasia identifies a subset of truly low-risk patients, for whom a conservative approach is advisable.

BRAF Mutations in Hairy-Cell Leukemia

BACKGROUND Hairy-cell leukemia (HCL) is a well-defined clinicopathological entity whose underlying genetic lesion is still obscure. METHODS We searched for HCL-associated mutations by performing massively parallel sequencing of the whole exome of leukemic and matched normal cells purified from the peripheral blood of an index patient with HCL. Findings were validated by Sanger sequencing in 47 additional patients with HCL. RESULTS Whole-exome sequencing identified five missense somatic clonal mutations that were confirmed on Sanger sequencing, including a heterozygous mutation in BRAF that results in the BRAF V600E variant protein. Since BRAF V600E is oncogenic in other tumors, further analyses were focused on this genetic lesion. The same BRAF mutation was noted in all the other 47 patients with HCL who were evaluated by means of Sanger sequencing. None of the 195 patients with other peripheral B-cell lymphomas or leukemias who were evaluated carried the BRAF V600E variant, including 38 patients with splenic marginal-zone lymphomas or unclassifiable splenic lymphomas or leukemias. In immunohistologic and Western blot studies, HCL cells expressed phosphorylated MEK and ERK (the downstream targets of the BRAF kinase), indicating a constitutive activation of the RAF-MEK-ERK mitogen-activated protein kinase pathway in HCL. In vitro incubation of BRAF-mutated primary leukemic hairy cells from 5 patients with PLX-4720, a specific inhibitor of active BRAF, led to a marked decrease in phosphorylated ERK and MEK. CONCLUSIONS; The BRAF V600E mutation was present in all patients with HCL who were evaluated. This finding may have implications for the pathogenesis, diagnosis, and targeted therapy of HCL. (Funded by Associazione Italiana per la Ricerca sul Cancro and others.).

MYD88 L265P Somatic Mutation in Waldenström's Macroglobulinemia

BACKGROUND Waldenströms macroglobulinemia is an incurable, IgM-secreting lymphoplasmacytic lymphoma (LPL). The underlying mutation in this disorder has not been delineated. METHODS We performed whole-genome sequencing of bone marrow LPL cells in 30 patients with Waldenströms macroglobulinemia, with paired normal-tissue and tumor-tissue sequencing in 10 patients. Sanger sequencing was used to validate the findings in samples from an expanded cohort of patients with LPL, those with other B-cell disorders that have some of the same features as LPL, and healthy donors. RESULTS Among the patients with Waldenströms macroglobulinemia, a somatic variant (T→C) in LPL cells was identified at position 38182641 at 3p22.2 in the samples from all 10 patients with paired tissue samples and in 17 of 20 samples from patients with unpaired samples. This variant predicted an amino acid change (L265P) in MYD88, a mutation that triggers IRAK-mediated NF-κB signaling. Sanger sequencing identified MYD88 L265P in tumor samples from 49 of 54 patients with Waldenströms macroglobulinemia and in 3 of 3 patients with non-IgM-secreting LPL (91% of all patients with LPL). MYD88 L265P was absent in paired normal tissue samples from patients with Waldenströms macroglobulinemia or non-IgM LPL and in B cells from healthy donors and was absent or rarely expressed in samples from patients with multiple myeloma, marginal-zone lymphoma, or IgM monoclonal gammopathy of unknown significance. Inhibition of MYD88 signaling reduced IκBα and NF-κB p65 phosphorylation, as well as NF-κB nuclear staining, in Waldenströms macroglobulinemia cells expressing MYD88 L265P. Somatic variants in ARID1A in 5 of 30 patients (17%), leading to a premature stop or frameshift, were also identified and were associated with an increased disease burden. In addition, 2 of 3 patients with Waldenströms macroglobulinemia who had wild-type MYD88 had somatic variants in MLL2. CONCLUSIONS MYD88 L265P is a commonly recurring mutation in patients with Waldenströms macroglobulinemia that can be useful in differentiating Waldenströms macroglobulinemia and non-IgM LPL from B-cell disorders that have some of the same features. (Funded by the Peter and Helen Bing Foundation and others.).

Analysis of the chronic lymphocytic leukemia coding genome: role of NOTCH1 mutational activation

Next generation sequencing and copy number analysis provide insights into the complexity of the CLL coding genome, and reveal an association between NOTCH1 mutational activation and poor prognosis.

Follicular Lymphoma International Prognostic Index 2: A New Prognostic Index for Follicular Lymphoma Developed by the International Follicular Lymphoma Prognostic Factor Project

PURPOSE The aim of the F2 study was to verify whether a prospective collection of data would enable the development of a more accurate prognostic index for follicular lymphoma (FL) by using parameters which could not be retrospectively studied before, and by choosing progression-free survival (PFS) as principal end point. PATIENTS AND METHODS Between January 2003 and May 2005, 1,093 patients with a newly diagnosed FL were registered and 942 individuals receiving antilymphoma therapy were selected as the study population. The variables we used for score definition were selected by means of bootstrap resampling procedures on 832 patients with complete data. Procedures to select the model that would minimize errors were also performed. RESULTS After a median follow-up of 38 months, 261 events for PFS evaluation were recorded. beta2-microglobulin higher than the upper limit of normal, longest diameter of the largest involved node longer than 6 cm, bone marrow involvement, hemoglobin level lower than 12 g/dL, and age older than 60 years were factors independently predictive for PFS. Using these variables, a prognostic model was devised to identify three groups at different levels of risk. The 3-year PFS rate was 91%, 69%, and 51% for patients at low, intermediate, and high risk, respectively (log-rank = 64.6; P < .00001). The 3-year survival rate was 99%, 96%, and 84% for patients at low, intermediate, and high risk, respectively (P < .0001). CONCLUSION Follicular Lymphoma International Prognostic Index 2 is a simple prognostic index based on easily available clinical data and may represent a promising new tool for the identification of patients with FL at different risk in the era of immunochemotherapy.

A prospective study of 338 patients with polycythemia vera: the impact of JAK2 (V617F) allele burden and leukocytosis on fibrotic or leukemic disease transformation and vascular complications

We studied the relationship between JAK2 (V617F) mutant allele burden and clinical phenotype, disease progression and survival in patients with polycythemia vera (PV). The percentage of granulocyte mutant alleles was evaluated using a quantitative real-time polymerase chain reaction-based allelic discrimination assay. Of the 338 patients enrolled in this prospective study, 320 (94.7%) carried the JAK2 (V617F) mutation. Direct relationships were found between mutant allele burden and hemoglobin concentration (P=0.001), white blood cell count (P=0.001), spleen size (P=0.001) and age-adjusted bone marrow cellularity (P=0.002), while an inverse relationship was found with platelet count (P<0.001). During the study period, eight patients progressed to post-PV myelofibrosis (MF) (all carrying >50% mutant alleles), while 10 patients developed acute myeloid leukemia (AML). The mutant allele burden was significantly related to the risk of developing myelofibrosis (P=0.029) and retained its significant effect also in multivariable analysis (P=0.03). By contrast, the risk of developing AML as well as that of thrombosis was not significantly related to mutant allele burden. Leukocytosis did not affect thrombosis, MF, leukemia or survival. In conclusion, a JAK2 (V617F) allele burden >50% represents a risk factor for progression to MF in PV.

Role of Anti-Hepatitis C Virus (HCV) Treatment in HCV-Related, Low-Grade, B-Cell, Non-Hodgkin's Lymphoma: A Multicenter Italian Experience

PURPOSE Hepatitis C virus (HCV) is endemic in some areas of Northwestern Europe and the United States. HCV has been shown to play a role in the development of both hepatocellular carcinoma and B-cell non-Hodgkins lymphoma (B-NHL). The biologic mechanisms underlying the lymphomagenic activity of the virus so far are under investigation. In this study, the role of antiviral (anti-HCV) treatment in B-NHL associated with HCV infection is evaluated. PATIENTS AND METHODS Thirteen patients with histologically proven low-grade B-NHL characterized by an indolent course (ie, doubling time no less than 1 year, no bulky disease) and carrying HCV infection were enrolled on the study. All patients underwent antiviral treatment alone with pegilated interferon and ribavirin. Response assessment took place at 6 and 12 months. RESULTS Of the twelve assessable patients, seven (58%) achieved complete response and two (16%) partial hematologic response at 14.1 +/- 9.7 months (range, 2 to 24 months, median follow-up, 14 months), while two had stable disease with only one patient experiencing progression of disease. Hematologic responses (complete and partial, 75%) were highly significantly associated to clearance or decrease in serum HCV viral load following treatment (P = .005). Virologic response was more likely to be seen in HCV genotype 2 (P = .035), while hematologic response did not correlate with the viral genotype. Treatment-related toxicity did not cause discontinuation of therapy in all but two patients, one of whom, however, achieved complete response. CONCLUSION This experience strongly provides a role for antiviral treatment in patients affected by HCV-related, low-grade, B-cell NHL.

MYD88 L265P in Waldenström macroglobulinemia, immunoglobulin M monoclonal gammopathy, and other B-cell lymphoproliferative disorders using conventional and quantitative allele-specific polymerase chain reaction

By whole-genome and/or Sanger sequencing, we recently identified a somatic mutation (MYD88 L265P) that stimulates nuclear factor κB activity and is present in >90% of Waldenström macroglobulinemia (WM) patients. MYD88 L265P was absent in 90% of immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance (MGUS) patients. We therefore developed conventional and real-time allele-specific polymerase chain reaction (AS-PCR) assays for more sensitive detection and quantification of MYD88 L265P. Using either assay, MYD88 L265P was detected in 97 of 104 (93%) WM and 13 of 24 (54%) IgM MGUS patients and was either absent or rarely expressed in samples from splenic marginal zone lymphoma (2/20; 10%), CLL (1/26; 4%), multiple myeloma (including IgM cases, 0/14), and immunoglobulin G MGUS (0/9) patients as well as healthy donors (0/40; P < 1.5 × 10(-5) for WM vs other cohorts). Real-time AS-PCR identified IgM MGUS patients progressing to WM and showed a high rate of concordance between MYD88 L265P ΔCT and BM disease involvement (r = 0.89, P = .008) in WM patients undergoing treatment. These studies identify MYD88 L265P as a widely present mutation in WM and IgM MGUS patients using highly sensitive and specific AS-PCR assays with potential use in diagnostic discrimination and/or response assessment. The finding of this mutation in many IgM MGUS patients suggests that MYD88 L265P may be an early oncogenic event in WM pathogenesis.

The coding genome of splenic marginal zone lymphoma: activation of NOTCH2 and other pathways regulating marginal zone development

Notch2 mutations represent the most frequent lesion in splenic marginal zone lymphoma.

Prognostic factors for thrombosis, myelofibrosis, and leukemia in essential thrombocythemia: a study of 605 patients

The findings from this study on a large series of patients treated according to current clinical practice provide reassurance that essential thrombocythemia is an indolent disorder and affected patients have a long survival. Background Essential thrombocythemia is a chronic myeloproliferative disorder; patients with this disorder have a propensity to develop thrombosis, myelofibrosis, and leukemia. Design and Methods We studied 605 patients with essential thrombocythemia (follow-up 4596 person-years) with the aim of defining prognostic factors for thrombosis, myelofibrosis, and leukemia during follow-up. Results Sixty-six patients (11%) developed thrombosis with a 10-year risk of 14%. Age >60 years (p<0.001) and a history of thrombosis (p=0.03) were independent risk factors for thrombosis. Progression to myelofibrosis occurred in 17 patients (2.8%) with a 10-year risk of 3.9%. Anemia at diagnosis of essential thrombocythemia was significantly correlated (p<0.001) with progression to myelofibrosis. Leukemia occurred in 14 patients (2.3%) at a median time of 11 years after the diagnosis of essential thrombocythemia; the risk was 2.6% at 10 years. Age >60 years (p=0.02) was significantly correlated with the development of leukemia. Cytotoxic treatment did not imply a higher risk of leukemia. At the time of the analysis, 64 of the 605 patients (10.6%) had died. The 10-year probability of survival was 88%, with a median survival of 22.3 years. Age >60 years (p<0.001) and history of thrombosis (p=0.001) were independent risk factors for survival. Conclusions The findings from this study on a large series of patients treated according to current clinical practice provide reassurance that essential thrombocythemia is an indolent disorder and affected patients have a long survival. The main risk is thrombosis, while myelofibrosis and leukemia are rare and late complications.