José A. Queizán

Molecular stratification model for prognosis in cytogenetically normal acute myeloid leukemia

We have evaluated 9 new molecular markers (ERG, EVI1, MLL-PTD, MN1, PRAME, RHAMM, and WT1 gene-expression levels plus FLT3 and NPM1 mutations) in 121 de novo cytogenetically normal acute myeloblastic leukemias. In the multivariate analysis, high ERG or EVI1 and low PRAME expressions were associated with a shorter relapse-free survival (RFS) and overall survival (OS). A 0 to 3 score was given by assigning a value of 0 to favorable parameters (low ERG, low EVI1, and high PRAME) and 1 to adverse parameters. This model distinguished 4 subsets of patients with different OS (2-year OS of 79%, 65%, 46%, and 27%; P = .001) and RFS (2-year RFS of 92%, 65%, 49%, and 43%; P = .005). Furthermore, this score identified patients with different OS (P = .001) and RFS (P = .013), even within the FLT3/NPM1 intermediate-risk/high-risk subgroups. Here we propose a new molecular score for cytogenetically normal acute myeloblastic leukemias, which could improve patient risk-stratification.

Long FLT3 internal tandem duplications and reduced PML-RARα expression at diagnosis characterize a high-risk subgroup of acute promyelocytic leukemia patients

Background Internal tandem duplications of the FLT3 gene (FLT3-ITDs) are frequent in patients with acute promyelocytic leukemia (APL), however its clinical impact remains controversial. Design and Methods We analyzed the prognostic significance of FLT3-ITD mutant level and size, as well as FLT3-D835 point mutations, PML-RARα expression and other predictive factors in 129 APL patients at diagnosis enrolled on the Spanish LPA96 (n=43) or LPA99 (n=86) PETHEMA trials. Results FLT3-ITDs and D835 mutations were detected in 21% and 9% of patients, respectively. Patients with increased ITD mutant/wild-type ratio or longer ITD size displayed shorter 5-year relapse-free survival (RFS) (P=0.048 and P<0.0001, respectively). However, patients with D835 mutations did not show differences in RFS or overall survival (OS). Moreover, patients with initial normalized copy number (NCN) of PML-RARα transcripts less than the 25th percentile had adverse clinical features and shorter 5-year RFS (P<0.0001) and OS (P=0.004) compared to patients with higher NCN. Patients with low NCN showed increased incidence of ITDs (P=0.001), with higher ratios (P<0.0001) and/or longer sizes (P=0.007). Multivariate analysis showed that long FLT3-ITD (P=0.001), low PML-RARα levels (P=0.004) and elevated WBC counts (>10×109/L) (P=0.018) were independent predictors for shorter RFS. We identified a subgroup of patients with high WBC, long FLT3-ITD and low NCN of transcripts that showed an extremely bad prognosis (5-year RFS 23.4%, P<0.0001). Conclusions In conclusion, FLT3-ITD size and PML-RARα transcript levels at diagnosis could contribute to improve the risk stratification in APL.

BAALC is an important predictor of refractoriness to chemotherapy and poor survival in intermediate-risk acute myeloid leukemia (AML)

We have analyzed brain and acute leukemia, cytoplasmic (BAALC) gene expression and other genetic markers (ERG, EVI1, MN1, PRAME, WT1, FLT3, and NPM1 mutations) in 127 intermediate-risk acute myeloid leukemia (AML) patients: 98 cytogenetically normal and 29 with intermediate-risk cytogenetic alterations. High versus low BAALC expressers showed a higher refractoriness to induction treatment (31% vs 10%; p = .005), lower complete remission rate after salvage therapy (82% vs 97%; p = .010), and lower 3-year overall (23% vs 58%, p < .001) and relapse-free survival (26% vs 52%, p = .006). Similar results were found when cytogenetic subgroups were analyzed separately. Multivariate models confirmed the unfavorable prognosis of this marker. In conclusion, BAALC is a relevant prognostic marker in intermediate-risk AML.

High FOXO3a expression is associated with a poorer prognosis in AML with normal cytogenetics.

The PI3/AKT pathway is up-regulated in acute myeloid leukemia (AML), but its prognostic relevance in cytogenetically normal AML (CN-AML) is unclear. We evaluated RNA levels of AKT and two downstream substrates (FOXO3a-p27) in 110 de novo CN-AML, included in the Spanish PETHEMA therapeutic protocols. Patients with high FOXO3a gene expression displayed shorter OS (p=0.015) and RFS (p=0.048) than low FOXO3a expressers. Features selected in the multivariate analysis as having an independent prognostic value for a shorter survival were WBC>50x10(9)/L, age >65 years and high FOXO3a expression. We concluded that FOXO3a assessment could contribute to improve the molecular-based risk stratification in CN-AML.

The relevance of preferentially expressed antigen of melanoma (PRAME) as a marker of disease activity and prognosis in acute promyelocytic leukemia

Previous studies showed that the gene for preferentially expressed antigen (PRAME) is over-expressed in acute promyelocytic leukemia (APL). This study suggests that low PRAME expression defines a subgroup of APL patients with a short relapse-free survival. Background The gene for preferentially expressed antigen of melanoma (PRAME) has been shown to be over-expressed in acute promyelocytic leukemia, but its actual incidence and clinical impact are still unknown. Design and Methods We studied PRAME expression at diagnosis using real-time quantitative polymerase chain reaction in 125 patients with acute promyelocytic leukemia enrolled in the Spanish PETHEMA-96 (n=45) and PETHEMA-99 (n=80) clinical trials. In addition, PRAME expression was evaluated as a marker of disease activity in 225 follow-up samples from 67 patients with acute promyelocytic leukemia. Results At diagnosis, PRAME expression in patients with acute promyelocytic leukemia was significantly higher (p<0.001) than in patients with non-M3 acute myeloid leukemia (n=213) and in healthy controls (n=10). Furthermore, patients with acute promyelocytic leukemia with high PRAME expression had a favorable outcome. Thus, the 5-year relapse-free survival was better in patients with >100-fold PRAME expression (86% vs. 74%; p=0.03), and this cut-off established two sub-groups with different relapse-free survival rates among patients with a white cell count <109/L (5-year relapse-free survival 94% vs. 80%, p=0.01). This effect was similar in patients with a white cell count >109/L, although differences were not statistically significant. In multivariate analysis, white cell count >109/L (p<0.001), bone marrow blasts >90% (p=0.001), and PRAME expression <100-fold (p=0.009) were associated with short relapse-free survival. Samples at remission showed PRAME levels similar to those in normal controls while samples at relapse over-expressed PRAME again. Furthermore, 12/13 samples collected within the 6-month period preceding relapse showed a >10-fold increase in PRAME expression levels. Conclusions Low PRAME expression defines a subgroup of patients with acute promyelocytic leukemia with a short relapse-free survival. This marker could be useful as a secondary marker for monitoring patients with acute promyelocytic leukemia.

Incidence and clinical characteristics of myeloproliferative neoplasms displaying a PDGFRB rearrangement

The myeloproliferative neoplasms displaying a PDGFRB rearrangement are rare diseases derived from a haematopoietic stem cell. The goals of the study were to assess the incidence of these disorders and to define the clinical and biological characteristics as well as the response to the imatinib therapy.

Frontline treatment of follicular lymphoma with fludarabine, cyclophosphamide, and rituximab followed by rituximab maintenance: toxicities overcome its high antilymphoma effect. Results from a Spanish Cooperative Trial (LNHF-03)

We assessed the efficacy of fludarabine, cyclophosphamide, and rituximab in combination (FCR) as frontline treatment in patients with follicular lymphoma (FL) followed by rituximab maintenance. Seventy-five untreated patients with FL received FCR followed by maintenance with rituximab 375 mg/m2 weekly during 4 weeks and every 6 months for 2 years. The overall response rate was 100%, with 89% complete remission (CR) and 11% partial remission (PR). Molecular remission was observed in all but one patient. Only eight patients completed all therapy planned. With a median follow-up of 47 months, the 5-year overall survival (OS), progression-free survival (PFS), and event-free survival (EFS) were 77%, 93%, and 72%, respectively. Age below 60 and low Follicular Lymphoma International Prognostic Index (FLIPI) correlated with a better EFS. Ten patients died due to toxic complications. The FCR regimen is highly effective in untreated patients with FL, with 89% CR, including molecular responses, and a low progression rate. However, the high incidence of treatment-related mortality makes this regimen unsafe and it cannot be recommended as an upfront therapy in FL.

Influence of MBL-2 mutations in the infection risk of patients with follicular lymphoma treated with rituximab, fludarabine, and cyclophosphamide

The employment of current treatments based on chemotherapy and immunotherapy leads to inmunosuppression. The presence of mutations or polymorphisms in genes related to immune system might involve an additional disadvantage. The aim of the present study was to analyze mannose-binding lectin (MBL-2 gene) mutations and their association with severe infections and event-free survival in patients diagnosed with follicular lymphoma, treated uniformly, in the clinical trial LNHF-03. The results of this trial showed impressive clinical efficacy but was complicated with 80 documented infectious episodes. Patients were classified into two genotypic groups, AA and AO/OO, based on their haplotypic inheritance. Neither the number of infectious episodes nor differences in event-free survival was found as a function of MBL-2 groups. Other factors, including the lymphoma malignancy and the immune alterations associated with the disease, should be considered responsible for this observation.

Next-generation sequencing and FISH studies reveal the appearance of gene mutations and chromosomal abnormalities in hematopoietic progenitors in chronic lymphocytic leukemia

BackgroundChronic lymphocytic leukemia (CLL) is a highly genetically heterogeneous disease. Although CLL has been traditionally considered as a mature B cell leukemia, few independent studies have shown that the genetic alterations may appear in CD34+ hematopoietic progenitors. However, the presence of both chromosomal aberrations and gene mutations in CD34+ cells from the same patients has not been explored.MethodsAmplicon-based deep next-generation sequencing (NGS) studies were carried out in magnetically activated-cell-sorting separated CD19+ mature B lymphocytes and CD34+ hematopoietic progenitors (n = 56) to study the mutational status of TP53, NOTCH1, SF3B1, FBXW7, MYD88, and XPO1 genes. In addition, ultra-deep NGS was performed in a subset of seven patients to determine the presence of mutations in flow-sorted CD34+CD19− early hematopoietic progenitors. Fluorescence in situ hybridization (FISH) studies were performed in the CD34+ cells from nine patients of the cohort to examine the presence of cytogenetic abnormalities.ResultsNGS studies revealed a total of 28 mutations in 24 CLL patients. Interestingly, 15 of them also showed the same mutations in their corresponding whole population of CD34+ progenitors. The majority of NOTCH1 (7/9) and XPO1 (4/4) mutations presented a similar mutational burden in both cell fractions; by contrast, mutations of TP53 (2/2), FBXW7 (2/2), and SF3B1 (3/4) showed lower mutational allele frequencies, or even none, in the CD34+ cells compared with the CD19+ population. Ultra-deep NGS confirmed the presence of FBXW7, MYD88, NOTCH1, and XPO1 mutations in the subpopulation of CD34+CD19− early hematopoietic progenitors (6/7). Furthermore, FISH studies showed the presence of 11q and 13q deletions (2/2 and 3/5, respectively) in CD34+ progenitors but the absence of IGH cytogenetic alterations (0/2) in the CD34+ cells. Combining all the results from NGS and FISH, a model of the appearance and expansion of genetic alterations in CLL was derived, suggesting that most of the genetic events appear on the hematopoietic progenitors, although these mutations could induce the beginning of tumoral cell expansion at different stage of B cell differentiation.ConclusionsOur study showed the presence of both gene mutations and chromosomal abnormalities in early hematopoietic progenitor cells from CLL patients.

Validation of the NCCN-IPI for diffuse large B-cell lymphoma (DLBCL): the addition of β2 -microglobulin yields a more accurate GELTAMO-IPI.

The study included 1848 diffuse large B‐cell lymphoma (DLBCL)patients treated with chemotherapy/rituximab. The aims were to validate the National Comprehensive Cancer Network International Prognostic Index (NCCN‐IPI) and explore the effect of adding high Beta‐2 microglobulin (β2M), primary extranodal presentation and intense treatment to the NCCN‐IPI variables in order to develop an improved index. Comparing survival curves, NCCN‐IPI discriminated better than IPI, separating four risk groups with 5‐year overall survival rates of 93%, 83%, 67% and 49%, but failing to identify a true high‐risk population. For the second aim the series was split into training and validation cohorts: in the former the multivariate model identified age, lactate dehydrogenase, Eastern Cooperative Oncology Group performance status, Stage III‐IV, and β2M as independently significant, whereas the NCCN‐IPI‐selected extranodal sites, primary extranodal presentation and intense treatments were not. These results were confirmed in the validation cohort. The Grupo Español de Linfomas/Trasplante de Médula ósea (GELTAMO)‐IPI developed here, with 7 points, significantly separated four risk groups (0, 1–3, 4 or ≥5 points) with 11%, 58%, 17% and 14% of patients, and 5‐year overall survival rates of 93%, 79%, 66% and 39%, respectively. In the comparison GELTAMO IPI discriminated better than the NCCN‐IPI. In conclusion, GELTAMO‐IPI is more accurate than the NCCN‐IPI and has statistical and practical advantages in that the better discrimination identifies an authentic high‐risk group and is not influenced by primary extranodal presentation or treatments of different intensity.