Carmen Pedro

Cytogenetic risk stratification in chronic myelomonocytic leukemia

Background The prognostic value of cytogenetic findings in chronic myelomonocytic leukemia is unclear. Our purpose was to evaluate the independent prognostic impact of cytogenetic abnormalities in a large series of patients with chronic myelomonocytic leukemia included in the database of the Spanish Registry of Myelodysplastic Syndromes. Design and Methods We studied 414 patients with chronic myelomonocytic leukemia according to WHO criteria and with a successful conventional cytogenetic analysis at diagnosis. Different patient and disease characteristics were examined by univariate and multivariate methods to establish their relationship with overall survival and evolution to acute myeloid leukemia. Results Patients with abnormal karyotype (110 patients, 27%) had poorer overall survival (P=0.001) and higher risk of acute myeloid leukemia evolution (P=0.010). Based on outcome analysis, three cytogenetic risk categories were identified: low risk (normal karyotype or loss of Y chromosome as a single anomaly), high risk (presence of trisomy 8 or abnormalities of chromosome 7, or complex karyotype), and intermediate risk (all other abnormalities). Overall survival at five years for patients in the low, intermediate, and high risk cytogenetic categories was 35%, 26%, and 4%, respectively (P<0.001). Multivariate analysis confirmed that this new CMML-specific cytogenetic risk stratification was an independent prognostic variable for overall survival (P=0.001). Additionally, patients belonging to the high-risk cytogenetic category also had a higher risk of acute myeloid leukemia evolution on univariate (P=0.001) but not multivariate analysis. Conclusions Cytogenetic findings have a strong prognostic impact in patients with chronic myelomonocytic leukemia.

Favorable outcome of patients with acute myeloid leukemia harboring a low-allelic burden FLT3-ITD mutation and concomitant NPM1 mutation: relevance to post-remission therapy

Risk associated to FLT3 internal tandem duplication (FLT3-ITD) in patients with acute myeloid leukemia (AML) may depend on mutational burden and its interaction with other mutations. We analyzed the effect of FLT3-ITD/FLT3 wild-type (FLT3wt) ratio depending on NPM1 mutation (NPM1mut) in 303 patients with intermediate-risk cytogenetics AML treated with intensive chemotherapy. Among NPM1mut patients, FLT3wt and low ratio (<0.5) subgroups showed similar overall survival, relapse risk, and leukemia-free survival, whereas high ratio (≥0.5) patients had a worse outcome. In NPM1wt AML, FLT3-ITD subgroups showed a comparable outcome, with higher risk of relapse and shortened overall survival than FLT3wt patients. Allogeneic stem cell transplantation in CR1 was associated with a reduced relapse risk in all molecular subgroups with the exception of NPM1mut AML with absent or low ratio FLT3-ITD. In conclusion, effect of FLT3 burden is modulated by NPM1 mutation, especially in patients with a low ratio.

Gastrointestinal Involvement in Mantle Cell Lymphoma: A Prospective Clinic, Endoscopic, and Pathologic Study

The frequency of gastrointestinal (GI) tract involvement in mantle cell lymphoma (MCL) at diagnosis is reported to be below 30%. To investigate the actual frequency of GI involvement by MCL, upper and lower endoscopy was prospectively performed on 13 untreated MCL patients at diagnosis. Multiple biopsies from endoscopically normal and abnormal gastric and colonic mucosa were studied with immunohistochemistry (IHC) for CD20, CD5, and cyclin D1, as well as fluorescence in situ hybridization (FISH) for t(11;14) and polymerase chain reaction (PCR) for immunoglobulin heavy chain gene. Abnormal mucosa was identified in 38% of cases by upper endoscopy (mainly mild nonspecific gastritis) and in 54% of cases by lower endoscopy (mostly micropolyps). Histologically, infiltration by MCL was demonstrated in the stomach in 77% of cases and in the colon in 77% of cases. As a whole, 92% of patients showed upper or lower GI tract infiltration by MCL. Histologic evidence of MCL involvement was present in all cases with endoscopically abnormal mucosa, but it was also observed in two-thirds of cases with endoscopically unremarkable mucosa. Positive cyclin D1 IHC was seen in all instances displaying CD20 and CD5-positive lymphoid infiltrates, whereas t(11;14) was demonstrated by FISH in 63.5% and PCR was clonal in 64% of those instances. In conclusion, the great majority of MCL patients showed GI tract involvement at the time of diagnosis, not uncommonly in the form of minute lymphoid infiltrates. IHC for cyclin D1 was significantly more sensitive than FISH t(11;14) or PCR for immunoglobulin heavy chain gene to confirm MCL in this setting.

Response to lenalidomide in myelodysplastic syndromes with del(5q): influence of cytogenetics and mutations

Lenalidomide is an effective drug in low‐risk myelodysplastic syndromes (MDS) with isolated del(5q), although not all patients respond. Studies have suggested a role for TP53 mutations and karyotype complexity in disease progression and outcome. In order to assess the impact of complex karyotypes on treatment response and disease progression in 52 lenalidomide‐treated patients with del(5q) MDS, conventional G‐banding cytogenetics (CC), single nucleotide polymorphism array (SNP‐A), and genomic sequencing methods were used. SNP‐A analysis (with control sample, lymphocytes CD3+, in 30 cases) revealed 5q losses in all cases. Other recurrent abnormalities were infrequent and were not associated with lenalidomide responsiveness. Low karyotype complexity (by CC) and a high baseline platelet count (>280 × 109/l) were associated with the achievement of haematological response (P = 0·020, P = 0·013 respectively). Unmutated TP53 status showed a tendency for haematological response (P = 0·061). Complete cytogenetic response was not observed in any of the mutated TP53 cases. By multivariate analysis, the most important predictor for lenalidomide treatment failure was a platelet count <280 × 109/l (Odds Ratio = 6·17, P = 0·040). This study reveals the importance of a low baseline platelet count, karyotypic complexity and TP53 mutational status for response to lenalidomide treatment. It supports the molecular study of TP53 in MDS patients treated with lenalidomide.

Rapid infusion of rituximab with or without steroid-containing chemotherapy: 1-yr experience in a single institution

Abstract:  We assessed the feasibility of a rapid infusion of rituximab with or without steroid‐containing chemotherapy. Inclusion criteria: previous infusion of rituximab without grade 3 or 4 toxicity, lymphoid cells <5 × 109/L and rituximab dose of 375 mg/m2. Seventy patients were treated with a total of 319 rapid rituximab infusions [126 (40%) with and 193 (60%) without steroids]. Overall, rapid infusion of rituximab was well tolerated – there were no grade 3 or 4 adverse events. Only, three patients developed symptoms, all grade 1. In conclusion, rituximab administration in a 90‐min infusion schedule is well tolerated and safe, both in patients who are administered steroids and in patients who are not.

Postpolycythaemic myelofibrosis: frequency and risk factors for this complication in 116 patients

Postpolycythaemic myelofibrosis (PPMF) is a known complication of polycythaemia vera (PV) but information regarding its incidence and predisposing factors is not well defined. In 116 subjects consecutively diagnosed with PV in a single institution (median age 62 years, range: 20–88), the probability of PPMF was analysed by the Kaplan–Meier method, followed by the log‐rank test. With a mean follow‐up of 8 years (95% confidence interval: 6·6–9), 17 patients had evolved into PPMF (15%). The probability of evolution to PPMF was 16% at 10 years and 34% at 15 years. Age, gender, spleen size, leucocytosis, thrombocytosis or cytoreductive treatment were not associated with an increased risk of PPMF. The actuarial probability of PPMF at 15 years was higher in those patients presenting at diagnosis with endogenous megakaryocytic colony formation (59% when present versus 10% when absent, P = 0·03), an elevated serum lactate dehydrogenase (LDH) level (69% vs. 23% in patients with normal LDH, P = 0·04), and in those who were heterozygous for the JAK2 V617F mutation (55% vs. 17% in heterozygotes, P = 0·04). In conclusion, PPMF is a frequent complication in PV patients at 15 years with the risk being higher in patients with increased LDH, endogenous megakaryocytic colony formation or a high JAK2 V617F allele burden.

Effectiveness of azacitidine in unselected high-risk myelodysplastic syndromes: results from the Spanish registry

The benefit of azacitidine treatment in survival of high-risk myelodysplastic syndromes (MDS) patients compared with conventional care treatment (CCT) has not been established outside clinical trials. To assess its effectiveness, we compared overall survival (OS) between azacitidine and conventional treatment (CCT) in high-risk MDS patients, excluding those undergoing stem cell transplantation, submitted to the Spanish MDS registry from 2000 to 2013. Several Cox regression and competing risk models, considering azacitidine as a time-dependent covariate, were used to assess survival and acute myeloblastic leukemia (AML) progression. Among 821 patients included, 251 received azacitidine. Median survival was 13.4 (11.8–16) months for azacitidine-treated patients and 12.2 (11–14.1) for patients under CCT (P=0.41). In a multivariate model, age, International prognostic scoring system and lactate dehydrogenase were predictors of OS whereas azacitidine was not (adjusted odds ratio 1.08, 95% confidence interval 0.86–1.35, P=0.49). However, in patients with chromosome 7 abnormalities, a trend toward a better survival was observed in azacitidine-treated patients (median survival 13.3 (11–18) months) compared with CCT (median survival 8.6 (5–10.4) months, P=0.08). In conclusion, our data show that, in spite of a widespread use of azacitidine, there is a lack of improvement in survival over the years. Identification of predicting factors of response and survival is mandatory.

Fluorescence in situ hybridization improves the detection of 5q31 deletion in myelodysplastic syndromes without cytogenetic evidence of 5q

The findings of this study indicate that fluorescence in situ hybridization improves the detection of deletion 5q31–32 in patients with myelodysplastic syndrome without cytogenetic evidence of del(5q). See related perspective on page 967. Background More than 50% of patients with myelodysplastic syndromes present cytogenetic aberrations at diagnosis. Partial or complete deletion of the long arm of chromosome 5 is the most frequent abnormality. The aim of this study was to apply fluorescence in situ hybridization of 5q31 in patients diagnosed with de novo myelodysplastic syndromes in whom conventional banding cytogenetics study had shown a normal karyotype, absence of metaphases or an abnormal karyotype without evidence of del(5q). Design and Methods We performed fluorescence in situ hybridization of 5q31 in 716 patients, divided into two groups: group A patients (n=637) in whom the 5q deletion had not been detected at diagnosis by conventional banding cytogenetics and group B patients (n=79), in whom cytogenetic analysis had revealed the 5q deletion (positive control group). Results In group A (n=637), the 5q deletion was detected by fluorescence in situ hybridization in 38 cases (5.96%). The majority of positive cases were diagnosed as having the 5q- syndrome. The deletion was mainly observed in cases in which the cytogenetics study had shown no metaphases or an aberrant karyotype with chromosome 5 involved. In group B (n=79), the 5q deletion had been observed by cytogenetics and was confirmed to be present in all cases by fluorescence in situ hybridization of 5q31. Conclusions Fluorescence in situ hybridization of 5q31 detected the 5q deletion in 6% of cases without clear evidence of del(5q) by conventional banding cytogenetics. We suggest that fluorescence in situ hybridization of 5q31 should be performed in cases of a suspected ‘5q- syndrome’ and/or if the cytogenetic study shows no metaphases or an aberrant karyotype with chromosome 5 involved (no 5q- chromosome).

Adverse impact of IDH1 and IDH2 mutations in primary AML: Experience of the Spanish CETLAM group

The study of genetic lesions in AML cells is helpful to define the prognosis of patients with this disease. This study analyzed the frequency and clinical impact of recently described gene alterations, isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2) mutations, in a series of homogeneously treated patients with primary (de novo) AML. Two-hundred and seventy-five patients enrolled in the CETLAM 2003 protocol were analyzed. IDH1 and IDH2 mutations were investigated by well-established melting curve-analysis and direct sequencing (R140 IDH2 mutations). To establish the percentage of the mutated allele a pyrosequencing method was used. Patients were also studied for NPM, FLT3, MLL, CEBPA, TET2 and WT1 mutations. IDH1 or IDH2 mutations were identified in 23.3% AML cases and in 22.5% of those with a normal karyotype. In this latter group, mutations were associated with short overall survival. This adverse effect was even more evident in patients with the NPM or CEBPA mutated/FLT3 wt genotype. In all the cases analyzed, the normal allele was detected, suggesting that both mutations act as dominant oncogenes. No adverse clinical impact was observed in cases with TET2 mutations. IDH1 and IDH2 mutations are common genetic alterations in normal karyotype AML. Favourable genotype NPM or CEBPA mutated/FLT3 wt can be further categorized according to the IDH1 and IDH2 mutational status.

Circulating erythroid and megakaryocytic progenitors in polycythaemia vera and essential thrombocythaemia

We studied the behaviour in culture of erythroid and megakaryocyte progenitor cells (BFU‐E, CFU‐MK) obtained from peripheral blood (PB) in 38 patients: 15 with essential thrombocythaemia, 3 with reactive thrombocytosis, 16 with polycythaemia vera and 4 with secondary polyglobulia. Clonal erythroid growth without added erythropoietin was observed in all patients with polycythaemia vera and in 5 out of 15 with essential thrombocythaemia, but in none of the patients with reactive thrombocytosis or secondary polyglobulia or in controls. When the CFU‐MK were cultured without phytohaemagglutinin‐stimulated medium (PHA‐LCM), all patients with essential thrombocythaemia and 7 out of 16 with polycythaemia vera showed circulating CFU‐MK but none of those with reactive thrombocytosis or secondary polyglobulia or controls did so. This study indicates that the growth in vitro of megakaryocyic and erythroid progenitors from such a readily available source as peripheral blood can be valuable in the diagnosis of certain borderline cases of thrombocytosis or erythrocytosis.