Survival Outcomes and Health-Related Quality of Life in Older Adults Diagnosed with Acute Myeloid Leukemia Receiving Frontline Therapy in Daily Practice.

Acute myeloid leukemia has a poor prognosis in older adults, and its management is often unclear due to its underrepresentation in clinical trials. Both overall survival (OS) and health-related quality-of-life (HRQoL) are key outcomes in this population, and patient-reported outcomes may contribute to patient stratification and treatment assignment. This prospective study included 138 consecutive patients treated in daily practice with the currently available non-targeted therapies (intensive chemotherapy [IC], attenuated chemotherapy [AC], hypomethylating agents [HMA], or palliative care [PC]). We evaluated patients' condition at diagnosis (Life expectancy [Lee Index for Older Adults], Geriatric Assessment in Hematology [GAH scale], HRQoL [EQ-5D-5L questionnaire], and fatigue [fatigue items of the QLQ-C30 scale]), OS, early death (ED), treatment tolerability (TT) and change in HRQoL over 12 months follow-up. The median OS was 7.1 months (IC not reached, AC 5.9, HMA 8.8, and PC 1.0). Poor risk AML category and receiving just palliative care, as well as a higher Lee index score in the patients receiving active therapy, independently predicted a shorter OS. The Lee Index and GAH scale were not useful for predicting TT. The white blood cell count was a valid predictor for ED. Patients' HRQoL remained stable during follow-up.

A novel Babesia sp. of the "Western Babesia group", detected in opossums from Guatemala.

Babesia spp. are tick-borne protozoans that involve birds and mammals in their transmission cycles and cause babesiosis, a severe hemolytic malaria-like disease. Opossums of the genus Didelphis are recognized hosts of tick-borne pathogens. Therefore, exploring tick-borne agents in Didelphis species is important to understand the circulation of pathogens in areas where opossums occur. In this study, we targeted Anaplasmataceae, Babesia, Borrelia and Hepatozoon DNA in ticks, blood and organ samples collected from three hunted Didelphis marsupialis specimens in eastern Guatemala. While the samples were negative for Hepatozoon and bacterial DNA, sequences of Babesia 18S rDNA, cox1 and cytb genes were retrieved from two opossums. Ticks collected on the animals included Amblyomma parvum and an undetermined Ornithodoros sp. The Babesia sp. detected in this study (Babesia sp. THB1-2) clusters phylogenetically within the "Western Babesia group", which includes pathogenic species such as Babesia conradae, Babesia duncani, and Babesia negevi. Our results represent the first record of a Babesia sp. in Guatemala and highlight the importance of D. marsupialis as potential spreaders of ticks and pathogens in Central America.

No Evidence that CD33 rs12459419 Polymorphism Predicts Gemtuzumab Ozogamicin Response in Consolidation Treatment of Acute Myeloid Leukemia Patients: Experience of the PETHEMA Group.

Gemtuzumab ozogamicin (GO) is a conjugate of a monoclonal antibody and calicheamicin, which has been reapproved for the treatment of acute myeloid leukemia (AML). AML patients with the CD33 rs12459419 CC genotype might benefit from the addition of GO to intensive treatment in contrast to patients with CT/TT genotypes. Nevertheless, contradictory results have been reported. We sought to shed light on the prediction of GO response in AML patients with rs12459419 polymorphism who were treated with GO in the consolidation (n = 70) or reinduction (n = 20) phase. The frequency distribution of the rs12459419 polymorphism in the complete cohort of patients was 44.4% (n = 40), 50% (n = 45), and 5.6% (n = 5) for CC, CT, and TT genotypes, respectively. Regarding the patients treated with GO for consolidation, we performed a Kaplan-Meier analysis of overall survival and relapse-free survival according to the rs12459419 polymorphism (CC vs. CT/TT patients) and genetic risk using the European Leukemia Net (ELN) 2010 risk score. We also carried out a Cox regression analysis for the prediction of overall survival, with age and ELN 2010 as covariates. We found no statistical significance in the univariate or multivariate analysis. Additionally, we performed a global Kaplan-Meier analysis for the patients treated with GO for reinduction and did not find significant differences; however, our cohort was too small to draw any conclusion from this analysis. The use of GO in consolidation treatment is included in the approval of the compound; however, evidence regarding its efficacy in this setting is lacking. Rs12459419 polymorphism could help in the selection of patients who might benefit from GO. Regrettably, in our cohort, the rs12459419 polymorphism does not seem to be an adequate tool for the selection of patients who might benefit from the addition of GO in consolidation cycles.

Relationship between malnutrition and the presence of symptoms of anxiety and depression in hospitalized cancer patients.

BACKGROUND: Anxiety and depression are a common issue in patients with cancer, yet understudied among hospitalized patients. The aim of this study was to estimate the prevalence of anxiety and depression symptomatology in cancer inpatients and its relationship with malnutrition. METHODS: Cross-sectional study in hospitalized cancer patients. A nutritional assessment was done using the Global Leadership Initiative on Malnutrition (GLIM) criteria to diagnose malnutrition. Data regarding anxiety and depression symptomatology was obtained with the Hospital Anxiety and Depression Scale (HADS). RESULTS: A total of 282 inpatients were assessed. GLIM criteria found 20% (66) of well-nourished and 80% (216) with malnutrition. HADS presented an average score of 8.3 ± 4.4 with respect to anxiety and an average score of 7.7 ± 4.6 with respect to depression. Up to 54% of the patients showed a possible presence of anxiety, and 45.3% of them showed a possible presence of depression. In malnourished patients, HADS score was non-significantly higher with respect to anxiety (8.5 ± 4.3 in malnourished vs 7.1 ± 4.6 in well-nourished; p = 0.06) and was significantly higher with respect to depression (8.2 ± 4.6 in malnourished vs 5.3 ± 4.0 in well-nourished; p < 0.001). After controlling for potential confounders, malnourished patients were 1.98 times more likely to present anxious symptomatology (95% CI 1.01-3.98; p = 0.049) and 6.29 times more likely to present depressive symptomatology (95% CI 1.73-20.47; p = 0.005). CONCLUSIONS: The presence of anxiety and depression symptomatology in oncological inpatients is high. There is an association between malnutrition and presenting anxious and depressive symptomatology in hospitalized cancer patients.

CT-Determined Sarcopenia in GLIM-Defined Malnutrition and Prediction of 6-Month Mortality in Cancer Inpatients.

Our objective was to evaluate the clinical application of third lumbar vertebra (L3)-computer tomography (CT)-determined sarcopenia as a marker of muscle mass in cancer inpatients diagnosed with malnutrition according to the Global Leadership Initiative on Malnutrition (GLIM) criteria and to establish its association with 6-month mortality. METHODS: This was an observational, prospective study in patients from an inpatient oncology unit. We performed a nutritional assessment according to GLIM criteria, including muscle cross-sectional area at L3 by CT and skeletal muscle index (SMI). Six-month mortality was evaluated. RESULTS: A total of 208 patients were included. The skeletal muscle cross-sectional area at L3 was 136.2 ± 32.5 cm2 in men and 98.1 ± 21.2 cm2 in women. The SMI was 47.4 ± 12.3 cm2/m2 in men and 38.7 ± 8.3 cm2/m2 in women. Sarcopenia (low SMI) was detected in 59.6% of the subjects. Using SMI as a marker of low muscle mass in application of GLIM criteria, we found 183 (87.9%) malnourished patients. There were 104 deaths (50%) at 6 months. The deceased patients had a lower skeletal muscle cross-sectional area (112.9 ± 27.9 vs. 126.1 ± 37.8 cm2; p = 0.003) and a lower SMI (41.3 ± 9.5 vs. 45.7 ± 12.9 cm2/m2; p = 0.006). An increased risk of 6-month mortality was found in malnourished patients according to GLIM criteria using SMI (HR 2.47; 95% confidence interval 1.07-5.68; p = 0.033). CONCLUSIONS: Low muscle mass, assessed by L3-CT, was observed to affect more than half of cancer inpatients. The deceased patients at 6 months had a lower skeletal muscle cross-sectional area and SMI. Malnutrition according to GLIM criteria using CT-determined sarcopenia was shown to adequately predict 6-month mortality.

Impact of measurable residual disease by decentralized flow cytometry: a PETHEMA real-world study in 1076 patients with acute myeloid leukemia.

The role of decentralized assessment of measurable residual disease (MRD) for risk stratification in acute myeloid leukemia (AML) remains largely unknown, and so it does which methodological aspects are critical to empower the evaluation of MRD with prognostic significance, particularly if using multiparameter flow cytometry (MFC). We analyzed 1076 AML patients in first remission after induction chemotherapy, in whom MRD was evaluated by MFC in local laboratories of 60 Hospitals participating in the PETHEMA registry. We also conducted a survey on technical aspects of MRD testing to determine the impact of methodological heterogeneity in the prognostic value of MFC. Our results confirmed the recommended cutoff of 0.1% to discriminate patients with significantly different cumulative-incidence of relapse (-CIR- HR:0.71, P < 0.001) and overall survival (HR: 0.73, P = 0.001), but uncovered the limited prognostic value of MFC based MRD in multivariate and recursive partitioning models including other clinical, genetic and treatment related factors. Virtually all aspects related with methodological, interpretation, and reporting of MFC based MRD testing impacted in its ability to discriminate patients with different CIR. Thus, this study demonstrated that "real-world" assessment of MRD using MFC is prognostic in patients at first remission, and urges greater standardization for improved risk-stratification toward clinical decisions in AML.

PLZF-RARα, NPM1-RARα, and Other Acute Promyelocytic Leukemia Variants: The PETHEMA Registry Experience and Systematic Literature Review.

It has been suggested that 1-2% of acute promyelocytic leukemia (APL) patients present variant rearrangements of retinoic acid receptor alpha (RARα) fusion gene, with the promyelocytic leukaemia zinc finger (PLZF)/RARα being the most frequent. Resistance to all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) has been suggested in PLZF/RARα and other variant APLs. Herein, we analyze the incidence, characteristics, and outcomes of variant APLs reported to the multinational PETHEMA (Programa para el Tratamiento de Hemopatias Malignas) registry, and we perform a systematic review in order to shed light on strategies to improve management of these extremely rare diseases. Of 2895 patients with genetically confirmed APL in the PETHEMA registry, 11 had variant APL (0.4%) (9 PLZF-RARα and 2 NPM1-RARα), 9 were men, with median age of 44.6 years (3 months to 76 years), median leucocytes (WBC) 16.8 × 109/L, and frequent coagulopathy. Eight patients were treated with ATRA plus chemotherapy-based regimens, and 3 with chemotherapy-based. As compared to previous reports, complete remission and survival was slightly better in our cohort, with 73% complete remission (CR) and 73% survival despite a high relapse rate (43%). After analyzing our series and performing a comprehensive and critical review of the literature, strong recommendations on appropriate management of variant APL are not possible due to the low number and heterogeneity of patients reported so far.

GLIM Criteria Using Hand Grip Strength Adequately Predict Six-Month Mortality in Cancer Inpatients.

Protein-calorie malnutrition is very frequent in cancer patients and is associated with an increase in morbidity and mortality. Recently, the Global Leadership Initiative on Malnutrition (GLIM) criteria were proposed to standardize the diagnosis of malnutrition. Nevertheless, these criteria were not validated in prospective studies. Our objective is to determine the prevalence of malnutrition in cancer inpatients using different diagnostic classifications, including GLIM criteria, and to establish their association with length of stay and mortality. Hence, we designed a prospective study. Within the first 24 hours of admission to the Inpatient Oncology Unit, subjective global assessment (SGA) was carried out, and anthropometric data (body mass index (BMI), mid-arm circumference (MAC), arm muscle circumference (AMC), fat-free mass index (FFMI)) and hand grip strength (HGS) were obtained to assess the reduction of muscle mass according to GLIM criteria. Length of stay, biomarkers (albumin, prealbumin, C-reactive protein (CRP)), and in-hospital and six-month mortality were evaluated. Regarding the 282 patients evaluated, their mean age was 60.4 ± 12.6 years, 55.7% of them were male, and 92.9% had an advanced-stage tumor (17.7% stage III, 75.2% stage IV). According to SGA, 81.6% of the patients suffered from malnutrition (25.5% moderate malnutrition, and 56.1% severe malnutrition), and, based on GLIM criteria, malnutrition rate was between 72.2 and 80.0% depending on the used tool. Malnourished patients (regardless of the tool used) showed significantly worse values concerning BMI, length of stay, and levels of CRP/albumin, albumin, and prealbumin than normally nourished patients. In logistic regression, adjusted for confounding variables, the odds ratio of death at six months was significantly associated with malnutrition by SGA (odds ratio 2.73, confidence interval (CI) 1.35-5.52, p = 0.002), and by GLIM criteria calculating muscle mass with HGS (odds ratio 2.72, CI 1.37-5.40, p = 0.004) and FFMI (odds ratio 1.87, CI 1.01-3.48, p = 0.047), but not by MAC or AMC. The prevalence of malnutrition in advanced-stage cancer inpatients is very high. SGA and GLIM criteria, especially with HGS, are useful tools to diagnose malnutrition and have a similar predictive value regarding six-month mortality in cancer inpatients.

Real life outcomes of patients aged ≥75 years old with acute promyelocytic leukemia: experience of the PETHEMA registry.

Acute promyelocytic leukemia is infrequent among patients aged ≥75 years old, a population that is rarely eligible for clinical protocols. This study aims to analyze the treatment strategies and clinical outcomes of very old APL patients reported to the international PETHEMA registry. Between 1997 and 2017, among 2501 APL cases registered 120 were ≥75 years old. Treatment approaches were: AIDA regimen, 79 patients; ATRA alone, 23; 16, supportive care (SC) and 2, other strategies. Patients treated with AIDA were younger, had better ECOG and lower leukocytes. Complete remission (CR) was achieved in 65% of AIDA-group vs. 45% in the ATRA-group, being infections followed by bleeding the most frequent causes of induction death. Patients in CR after AIDA showed 3-year DFS of 73%. Our real-life series of very old APL patients provides a reference basis for future treatment strategies aiming to improve clinical outcomes in this challenging population.

Incidence and outcome after first molecular versus overt recurrence in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia included in the ALL Ph08 trial from the Spanish PETHEMA Group.

BACKGROUND: Disease recurrence occurs in 20% to 40% of adults with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) who are treated with chemotherapy and tyrosine kinase inhibitors (TKIs). In the current study, the authors report the incidence, treatment, and outcome after first disease recurrence in young and older adults treated in the ALL Ph08 trial (ClinicalTrials.gov identifier NCT01491763). METHODS: Patients aged 18 to 55 years with de novo Ph+ ALL were treated with imatinib concurrently with standard-dose induction and consolidation therapy followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) when possible. In patients with first disease recurrence, the authors analyzed the type of recurrence, timing, location, presence of kinase domain mutations, type of treatment, and outcomes. RESULTS: Of the 125 patients, 28 patients (22%) developed disease recurrence before (4 patients) or after (24 patients) HSCT, with the recurrences being molecular in 11 patients (39%) and overt in 17 patients (61%). T315I was the most common mutation noted at the time of disease recurrence. Change in TKI was the most frequent treatment for patients with molecular disease recurrence whereas rescue chemotherapy and TKI change followed by second allo-HSCT when possible were performed for the most part in patients with overt disease recurrence. A total of 20 patients (71%) achieved response. The median disease-free survival (DFS) and overall survival (OS) were 8.5 months and 15.3 months, respectively. A trend for better DFS and OS was observed in patients with molecular recurrence compared with those with overt recurrence (median of 16.9 months vs 6.3 months [P = .05] and 28.7 months vs 11.5 months [P = .05] for DFS and OS, respectively). CONCLUSIONS: Disease recurrence was frequent in young and older adults with Ph+ ALL who were treated with imatinib and chemotherapy with HSCT. Although the majority of patients responded to rescue therapy, their outcomes were poor, especially with regard to overt disease recurrence.

Correction: Earlier relapse detection after allogeneic haematopoietic stem cell transplantation by chimerism assays: Digital PCR versus quantitative real-time PCR of insertion/deletion polymorphisms.

[This corrects the article DOI: 10.1371/journal.pone.0212708.].

Earlier relapse detection after allogeneic haematopoietic stem cell transplantation by chimerism assays: Digital PCR versus quantitative real-time PCR of insertion/deletion polymorphisms.

BACKGROUND: The analysis of molecular haematopoietic chimerisms (HC) has become a well-established method to monitor the transplant evolution and to assess the risk of relapse after allogeneic stem cells transplantation (allo-STC). Different techniques and molecular markers are being used for chimerism surveillance after transplantation, including quantitative real-time PCR (qPCR) and the recently developed digital PCR (dPCR). This study aims to compare the sensitivity and accuracy of both methods to quantify HC and predict early relapse. METHODOLOGY: HC was evaluated using custom PCR systems for the specific detection of the Y-chromosome, null alleles and insertion-deletion polymorphisms. A total of 281 samples from 28 adult patients who underwent an allo-SCT were studied. Increasing mixed chimerism was detected prior to relapse in 100% of patients (18 relapses). RESULTS: Compared with conventional qPCR amplification, dPCR predicted relapse with a median anticipation period of 63 days versus 45.5 days by qPCR. Overall, 56% of the relapses were predicted earlier with dPCR whereas 38% of the relapses where detected simultaneously using both techniques and only in 1 case, relapse was predicted earlier with qPCR. CONCLUSIONS: In conclusion, chimerism determination by dPCR constitutes a suitable technique for the follow-up of patients with haematological pathologies after allo-STC, showing greater sensitivity to predict an early relapse.

Cocoa ingestion protects plasma lipids in healthy males against ex vivo oxidative conditions: A randomized clinical trial.

The effects of in vivo cocoa-based supplementation were studied as a preconditioning treatment for ex vivo acute oxidative conditions in a controlled randomized clinical trial. Subjects were 100 healthy young men at Universidad Industrial de Santander blinded to the intervention and divided into two groups: The intervention group (n = 50) receiving 30 g of cocoa powder and 50 g of dark chocolate/d for 1 week with the remaining subjects receiving placebo. Cocoa products preconditioning for 1 week resulted in modifications in the susceptibility of plasma lipids over ex vivo oxidative conditions with effects of i) a significant increase in the oxidative resistance of plasma lipids measured by dienes formation (4.2, CI: 0.18, 8.2; P = 0.04), and ii) a significant reduction in the production of toxic aldehydes as established by a decrease in the content of hexanal, quantified by gas chromatography (-0.22, CI: -0.38, -0.05; P = 0.009). The in vivo cocoa-based preconditioning demonstrated protective properties against ex vivo oxidative modifications, improving total plasma lipids resistance to oxidation and protecting plasma lipids against great acute oxidative insult in comparison with placebo. This trial was registered at clinical clinicaltrials.gov as NCT01347450.

Frequency and prognostic significance of additional cytogenetic abnormalities to the Philadelphia chromosome in young and older adults with acute lymphoblastic leukemia.

About 25-35% of adult patients with acute lymphoblastic leukemia show the Philadelphia (Ph) chromosome. Few series have evaluated the prognosis of additional cytogenetic alterations (ACA) to the Ph chromosome. We analyzed the frequency, type and prognostic significance ofACA in adults (18-60 years) treated in the ALL-Ph-08 trial. Fifty-two out of 74 patients (70%) showed ACA and 19 (26%) presented monosomies associated with t(9;22) (monosomal karyotype, MK). Similar complete response (CR) rate, CR duration, overall survival and event-free survival (EFS) were observed in patients with or without ACA, but patients with MK showed shorter CR duration and EFS than the remaining. On multivariate analysis, the only variable with prognostic impact for CR duration and EFS was the presence of MK (p = .003 and p = .036, respectively). Although ACA associated with the Ph chromosome are frequent, only monosomies were associated with poor prognosis in this group of patients.

Clinical characteristics of patients with central nervous system relapse in BCR-ABL1-positive acute lymphoblastic leukemia: the importance of characterizing ABL1 mutations in cerebrospinal fluid.

We investigated the frequency, predictors, and evolution of acute lymphoblastic leukemia (ALL) in patients with CNS relapse and introduced a novel method for studying BCR-ABL1 protein variants in cDNA from bone marrow (BM) and cerebrospinal fluid (CSF) blast cells. A total of 128 patients were analyzed in two PETHEMA clinical trials. All achieved complete remission after imatinib treatment. Of these, 30 (23%) experienced a relapse after achieving complete remission, and 13 (10%) had an isolated CNS relapse or combined CNS and BM relapses. We compared the characteristics of patients with and without CNS relapse and further analyzed CSF and BM samples from two of the 13 patients with CNS relapse. In both patients, classical sequencing analysis of the kinase domain of BCR-ABL1 from the cDNA of CSF blasts revealed the pathogenic variant p.L387M. We also performed ultra-deep next-generation sequencing (NGS) in three samples from one of the relapsed patients. We did not find the mutation in the BM sample, but we did find it in CSF blasts with 45% of reads at the time of relapse. These data demonstrate the feasibility of detecting BCR-ABL1 mutations in CSF blasts by NGS and highlight the importance of monitoring clonal evolution over time.

A prognostic model for survival after salvage treatment with FLAG-Ida +/- gemtuzumab-ozogamicine in adult patients with refractory/relapsed acute myeloid leukaemia.

The combination of fludarabine, cytarabine, idarubicin, and granulocyte colony-stimulating factor (FLAG-Ida) is widely used in relapsed/refractory acute myeloid leukaemia (AML). We retrospectively analysed the results of 259 adult AML patients treated as first salvage with FLAG-Ida or FLAG-Ida plus Gentuzumab-Ozogamicin (FLAGO-Ida) of the Programa Español de Tratamientos en Hematología (PETHEMA) database, developing a prognostic score system of survival in this setting (SALFLAGE score). Overall, 221 patients received FLAG-Ida and 38 FLAGO-Ida; 92 were older than 60 years. The complete remission (CR)/CR with incomplete blood count recovery (CRi) rate was 51%, with 9% of induction deaths. Three covariates were associated with lower CR/CRi: high-risk cytogenetics and t(8;21) at diagnosis, no previous allogeneic stem cell transplantation (allo-SCT) and relapse-free interval <1 year. Allo-SCT was performed in second CR in 60 patients (23%). The median overall survival (OS) of the entire cohort was 0·7 years, with 22% OS at 5-years. Four independent variables were used to construct the score: cytogenetics, FLT3-internal tandem duplication, length of relapse-free interval and previous allo-SCT. Using this stratification system, three groups were defined: favourable (26% of patients), intermediate (29%) and poor-risk (45%), with an expected 5-year OS of 52%, 26% and 7%, respectively. The SALFLAGE score discriminated a subset of patients with an acceptable long-term outcome using FLAG-Ida/FLAGO-Ida regimen. The results of this retrospective analysis should be validated in independent external cohorts.

Treatment of young patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia using increased dose of imatinib and deintensified chemotherapy before allogeneic stem cell transplantation.

The main outcomes of the Programa Español para Tratamiento de Hemopatías (PETHEMA)-acute lymphoblastic leukaemia (ALL)-Ph-08 trial were described and compared with those of the historical PETHEMA-CSTIBES02 trial. The trials differed in imatinib dose (600 vs. 400 mg/d) and amount of chemotherapy (one vs. two consolidation cycles) before stem cell transplantation (SCT). All patients (n = 29) enrolled in the ALL-Ph-08 trial achieved complete remission (CR) (vs. 90% in CSTIBES02), and SCT was performed in CR in 90% (vs. 78%). The reduction in early death, relapse before SCT and transplant-related mortality observed in the ALL-Ph-08 trial resulted in an improved 2-year event-free survival (63% vs. 37%, P = 0·009).

Poor prognosis in acute lymphoblastic leukemia may relate to promoter hypermethylation of cancer-related genes.

The hallmark of acute lymphoblastic leukemia (ALL) is a progressive appearance of malignant cell behavior that is triggered by the evolution of altered gene function. ALL has traditionally been viewed as a genetic disease; however, epigenetic defects also play an important role. DNA promoter methylation has gained increasing recognition as an important mechanism for transcriptional silencing of tumor-suppressor genes. Hypermethylation may contribute to the pathogenesis of leukemias providing an alternative route to gene mutation. We have reported that gene methylation in ALL cells is the most important way to inactivate cancer-related genes in this disease. In fact, this epigenetic event can help to inactivate tumor-suppressive apoptotic or growth-arresting responses and has prognostic impact in B- and T-ALL. The presence in individual tumors of multiple genes simultaneously methylated is an independent factor of poor prognosis in both childhood and adult ALL in terms of disease-free survival and overall survival. Moreover, methylation status is able to redefine the prognosis of selected ALL groups with well-established prognostic features.

Promoter hypomethylation of the LINE-1 retrotransposable elements activates sense/antisense transcription and marks the progression of chronic myeloid leukemia.

Aberrant genome-wide hypomethylation is thought to be related to tumorigenesis by promoting genomic instability. Since DNA methylation is considered an important mechanism for the silencing of retroelements, hypomethylation in human tumors may lead to their reactivation. However, the role of DNA hypomethylation in chronic myeloid leukemia (CML) remains to be elucidated. In this study, the methylation status of the LINE-1 (L1) retrotransposon promoter was analysed in CML samples from the chronic-phase (CP, n=140) and the blast crisis (BC, n=47). L1 hypomethylation was significantly more frequent in BC (74.5%) than in CP (38%) (P<0.0001). Furthermore, L1 hypomethylation led to activation of both ORF1 sense transcription (P<0.0001) and c-MET gene antisense transcription (P<0.0001), and was significantly associated with high levels of BCR-ABL (P=0.02) and DNMT3b4 (P=0.001) transcripts. Interestingly, in CP-CML, extensive L1 hypomethylation was associated with poorer prognosis in terms of cytogenetic response to interferon (P=0.004) or imatinib (P=0.034) and progression-free survival (P=0.005). The above results strongly suggest that activation of both sense and antisense transcriptions by aberrant promoter hypomethylation of the L1 elements plays a role in the progression and clinical behavior of the CML.