Objetivo: identificar los factores de riesgo para transformación a leucemia mieloide aguda (LMA) en pacientes con síndrome mielodisplásico (SMD) atendidos en la Clínica FOSCAL durante el periodo comprendido entre junio de 2013 y junio de 2019.Materiales y métodos: análisis secundario de una base de datos de pacientes mayores de 18 años diagnosticados con SMD en la población atendida en FOSCAL (2013-2019). Fueron incluidos todos los pacientes independientemente del tipo declasificación o tratamiento. Se realizó un análisis univariado descriptivo para la caracterización de la población y bivariado para la estimación de valor p según la variable desenlace progresión a LMA en pacientes con SMD; del total de pacientes, en ochono fue posible determinar este desenlace. Estudio aprobado por el comité de ética institucional (Acta 35 de 19/10/2018).

Introduction: Myelodysplastic syndromes (MDS) comprise a varied group of clonal myeloid neoplasms characterized by cytopenias and an increased risk of progression to acute myeloid leukemia. Prognosis is variable, but little is known about the clinical features of MDS in the Colombian population. The diverseness of the disease and changes in standardized diagnostic criteria throughout the years have hinder accurate case detection and epidemiologic evaluation of MDS in our population. Objective: The aim of the present study was to determine the clinical characteristics and evaluate the overall survival (OS) of patients with MDS treated at two large referral centers in Colombia. Methods: An observational, retrospective study was conducted at two tertiary care centers in Colombia. Patients diagnosed with MDS at Clinica FOSCAL and Hospital San Jose between June 2013 and June 2019 were selected. Descriptive statistics were used to analyze baseline demographic characteristics and clinical data such as disease classification, risk stratification, and treatment. The Kaplan-Meier method was used to assess overall (OS) at 1, 3 and 5 years. Results: A total of 96 patients were included. Median age at diagnosis was 75 years (range 31-104). Fifty-two (54.2%) patients were male. According to the 2016 World Health Organization classification of MDS, the most commonly diagnosed subtype was MDS with multilineage dysplasia (31.2%), followed by MDS with excess blasts (13.5%); however, 35.4% of patients had an unclassifiable MDS sub-type. Twenty-nine (31.2%) patients were screened for cytogenetic abnormalities, the most common chromosomal abnormalities were deletion in the long arm of chromosome 5 (4.2%) and deletion of 7q (2.1%). Therapy related MDS was diagnosed in 13 (13.5%) patients and secondary MDS associated to pesticides exposure in 2 (2.1%) patients. After stratifying patients by the International Prognostic Scoring System (IPSS), the majority of patients were in the intermediate risk group, with 21 (34.4%) and 16 (26.2%) patients in the intermediate-1 and intermediate-2 categories respectively. Almost 80% of the patients presented one or more comorbidities, the most common was cardiac disease (30.5%). Supportive care with erythropoiesis-stimulating agents was the most common first-line treatment (61.4%), followed by iron chelation therapy (6.2%). Forty-eight (50%) patients were treated with hypomethylating agents (HMA), 43.7% receiving azacytidine and 6.3% decitabine. Among HMA-treated patients, 49.6% were in the intermediate-2 and high-risk IPSS groups. Two patients underwent allogeneic hematopoietic stem cell transplantation. Only patients treated with HMA and cytarabine/idarubicin chemotherapy achieved a complete response (11.5%). OS at one- and five-years post-diagnosis was 73.4% and 40.7% (95%CI 62.4-81.6 and 27.1-53.9) respectively. Patients in the intermediate-2 and high-risk IPSS groups had lower survival rates compared to those in the low and intermediate-1 risk groups. The OS for patients treated with azacytidine was 77.2% (95%CI 60.7-87.5%) at one-year, 43.2% (95%CI 23.9-61.1%) at three-years, and 37.8% (95%CI 19.0-56.5) at five-years after diagnosis. The most common cause of death was infection (51.3%), followed by disease progression (24.3%). Conclusions: The OS of patients with MDS in our study is similar to the reported in the existing literature. Knowing the epidemiology, clinical characteristics, risk stratification, and disease outcomes of MDS patients in our population is crucial to decide the best treatment strategies and improve the clinical outcomes of our patients. Disclosures Sossa: Roche: Honoraria; Astellas: Honoraria; Takeda: Honoraria; Novo: Honoraria. Abello:Dr. Reddy's: Consultancy, Research Funding; Takeda: Honoraria, Research Funding; Amgen: Consultancy, Research Funding; Novartis: Consultancy, Honoraria; Abbvie: Consultancy, Research Funding. Peña:Roche: Honoraria. Salazar:Novartis: Honoraria; Janssen: Honoraria. Sandoval-Sus:Celgene: Speakers Bureau; Massive Bio: Consultancy; Janssen: Consultancy; MorphoSys US: Consultancy.

Introduction Acute lymphoblastic leukemia (ALL) is a clonal hematopoietic disorder that originates from B or T lymphoid progenitors and has well validated prognostic and predictive factors that influence outcomes. One of the strongest prognostic factors is the detection of minimal residual disease (MRD) which measures residual cell population after treatment when a morphologic complete response has been achieved. MRD positivity is associated with a higher risk of relapse and poor response to chemo or radiotherapy Objectives The aim of the study was to assess the prognostic impact of post-induction MRD status in a cohort of ALL Colombian patients in terms of relapse-free survival (RFS) and overall survival (OS). Methods This is a retrospective observational study conducted at a Colombian university hospital and included a cohort of ALL patients diagnosed between 2013 and 2020 treatment according to protocol PETHEMA (Spanish Program for Hematology Treatments). MRD was measured with 8-color flow cytometry evaluate on bone marrow. MRD status was classified as negative MRD (NMRD) or positive MRD (PMRD) based on a sensitivity threshold of <0,01% or ≥0,01% leukemic cells, respectively, following to international guides. Demographic and clinical characteristics were analyzed using descriptive statistics. Kaplan-Meier method was used to assess overall RFS and OS. Results A total 128 patients were included. The median age at diagnosis was 34 years (range 0-89 years), 54% were men, 26% were overweight, 22% obese, 6.2% had type 2 DM (T2DM), and most had a ECOG PS of £2 (94%). Most patients (80.5%) had high risk according PETHEMA, B-ALL and were classified as ALL-2 (58%) according to FAB classification with Pre-B cell ALL being the most common phenotype (54.7%). Ph+ ALL was diagnosed in 12% of patients. Most used treatments protocols were PETHEMA-AR and PETHEMA-RI in 43.8% and 11.6% of patients, respectively. Post-induction MRD measurement was available in 98 patients, 36 (36.7%) had NMRD and 62 (63.3%) PMRD. From the 36 patients with NMRD, eight patients (22.2%) received Allogeneic Hematopoietic Stem Cell Transplantation (alloHSCT): two of them, were transplanted in first complete remission, one because of high risk and the other one for BCR-ABL positivity. The other six patients received alloHSCT in second remission and all of them relapsed after late consolidations. Finally, alloHSCT was done in 28 patients with PMRD (45.2%). The 12-month OS for patients with NMRD was 68.7% (95%CI 50.5-81.2) compared to 63.7% (95%CI 50.3-74.4) in the ones with PMRD, p=0.375. 12-month RFS was 83.3% (95%CI 61.5-93.4) in patients with NMRD and 90.0% (95%CI 72.1-96.7) in patients with PMRD, p=0.436. (Figure 1). OS was significantly higher for the PMRD patients who underwent AlloHSCT 96.4% (95%CI 77.2-99.4) versus not underwent 36.8% (95%CI 20.6-53.2), HR: 0.39 (95%CI 0.005-0.29) p=0.002 (Figure 2). Conclusion MRD assessment is a strong prognostic in ALL, however it was not associated with significant differences in RFS or OS in this single institution cohort of Colombian patients. Patients with PMRD taken to AlloHSCT had superior OS compared to NMRD that underwent transplant. A small sample size and short follow-up could explain our results. Larger cohorts with extended follow up and with different MRD methods are needed to better understand the role of MRD assessment in minority ALL populations, such as Colombian patients. Figure 1 Figure 1. Disclosures Peña: Amgen: Research Funding. Salazar: Amgen: Research Funding. Sandoval-Sus: BMS: Other: Advisory Board, Speakers Bureau; SeaGen, Janssen, MassiveBio, TG: Other: Advisory Board. Sossa: Amgen: Research Funding.

INTRODUCTION Acute lymphoblastic leukemia (ALL) is a clonal hematopoietic disorder that originates from B or T lymphoid progenitors. It affects more frequently children, but prognosis is worse in adults. ALL has a high incidence in Hispanics (Swords R et al. Blood Cancer J. 2016) and is important to identify baseline clinical, sociodemographic, and cytogenetic characteristics in these patients that are relevant for relapse free and overall survival. Reports of Hispanic patients with ALL outsides of the U.S.A are scare but are important to further characterize the impact of this disease in minority populations. OBJETIVE To describe the association between sociodemographic, clinical and immunophenotypic variables with 12-month relapse free survival (RFS) and overall survival (OS) in patients diagnosed and treated for ALL in a Colombian university hospital (FOSCAL). MATERIALS AND METHODS This is a descriptive observational cohort study that included patients older than 18 years with a confirmed diagnosis of ALL treated in a tertiary university hospital between 2013-2020 and that had at least 12 months follow-up after starting treatment. Baseline sociodemographic, clinical, laboratory and immunophenotypic data were collected. Bivariate analyses of both relapse and mortality cumulative incidences at 12 months, with relative risks (RR) and their 95% Confidence intervals were performed, using either chi-square or Fischer exact test when needed. In a second term, bivariate survival analyses through Kaplan-Meier survival function and Hazard ratios were evaluated, using Cox proportional hazards as the main statistical test. RESULTS Among 128 of include patients, the median age at diagnosis was 34 years (range 0-89 years), 54% were men, 6.2% had type 2 Diabetes Mellitus (T2DM), most had an ECOG PS of 0 (72.7%), 31.8% had splenomegaly, 12% had hepatomegaly and 47% presented without organomegalies. The proportion of patients with overweight and obesity were 26.3% and 22.2% respectively. At diagnosis 80.5% and 8.8% of patients had high risk and standard risk ALL, respectively Forty-eight patients had a FAB classification with 58% being ALL-2 and most of the were unclassified. Most cases (81%) had B-cell immunophenotype, with 55% being pre-B-cell and 32% mature B-cell. Twelve percent of patients were Ph+ B-ALL. At 12 months, the proportion of mortality was 34.4%. Most of the patients (83%) did not have major co-morbidities, however patients with T2DM had a significantly inferior survival at 12 months, HR: 3.68 (95%CI 1.54-8.8 P=0.003), as patients older than 35 years (HR: 2.15, 95%CI: 1.14-4.0, P=0.017) (Table 1). CONCLUSIONS Colombian patients with B-cell ALL have similar clinical, immunophenotypic and cytogenetic (Ph+ prevalence) characteristics as seen in other international cohorts. In our cohort patients older than 35 years and subjects with T2DM had inferior survival at 1 year. Further analyses of socioeconomic factors, molecular features and response to specific regimens are needed to have a better understanding of Colombian B-ALL patients. Figure 1 Figure 1. Disclosures Salazar: Amgen: Research Funding. Peña: Amgen: Research Funding. Sandoval-Sus: BMS: Other: Advisory Board, Speakers Bureau; SeaGen, Janssen, MassiveBio, TG: Other: Advisory Board. Sossa: Amgen: Research Funding.