Understanding factors limiting hematopoietic cell transplantation for acute myeloid leukemia patients in Mexico: a comprehensive analysis.

Acute myeloid leukemia (AML) is the most frequent indication for allogeneic hematopoietic cell transplantation (alloHCT) worldwide; social and health system barriers limit its access. We performed an observational retrospective analysis in Mexico to analyze factors limiting alloHCT in fit patients with AML. With a median follow-up of 11.8 months, 301 patients were included, with a median age of 42; 33.5% were classified as adverse risk. Despite 215 patients (92.5%) achieving complete remission, only 103 (34%) had HLA-typing: 44.5% had a matched-sibling donor (MSD), 32% a haploidentical donor, and 23.5% had no donor. Only 23.5% of patients had an HCT consult; merely 36 underwent an HCT: 30 alloHCT, and six an autologous HCT. Age ≥ 60 years, HCT-CI score ≥ three, and the absence of a local transplant program negatively influenced HLA typing likelihood. Patients with an MSD had a higher alloHCT likelihood. The cumulative incidence of transplant (CIT) and relapse (CIR) at 6 and 12 months was 7.3% and 13.8%, 8.2% and 13%, respectively. A lack of HLA-typing was associated with a lower CIT (p < 0.001) and higher CIR (p = 0.033) (HR 11.72, CI 95% 4.39-31.27, p < 0.001), while the presence of an MSD was associated with a higher CIT (p = 0.002) (HR 4.22, CI 95% 1.89-9.44, p < 0.001). The main reasons hindering alloHCT are the lack of access to HLA-typing tests and the absence of an MSD. A national donor registry and improved HLA-typing accessibility are critical for increasing alloHCT access in Mexico.

Acute Myeloid Leukemia in Mexico: The Specific Challenges of a Developing Country. Results From a Multicenter National Registry.

BACKGROUND: In the past decades, long-term survival outcomes for younger patients with acute myeloid leukemia (AML) have improved. Nonetheless, developing nations might be lagging behind, highlighting the need to assess real-world outcomes in such regions. METHODS: We performed a multicenter retrospective study, which included patients with AML diagnosed between January 2013 and December 2017 from 13 centers in Mexico. RESULTS: A total of 525 patients with AML met the inclusion criteria and were included in the study. Median age for the entire cohort was 47 years. The patients were classified according to cytogenetic risk: favorable 16.0%, intermediate 55.6%, and unfavorable 28.4%. Most patients received intensive chemotherapy (80.2%), and among these 74.1% underwent a 7 + 3 induction regimen. A complete remission was achieved in 71.3% of patients. Induction-related mortality occurred in 17.8% and we identify the following as independent risk factors: >60 years (odds ratio [OR] 2.09 [1.09-4.02]), Eastern Cooperative Oncology Group >2 (OR 4.82 [2.46-9.43]), prior solid tumor (OR 3.8 [1.24-11.59]) and active infection (OR 1.82 [1.06-3.12]). Further, allogeneic hematopoietic stem-cell transplantation (AlloHSCT) was performed in 8.2% in CR1. The 3-year overall survival (OS) was 34.8%. In a multivariate analysis, several factors were independently associated with a worse OS, including secondary AML (hazard ratio [HR] 2.14 [1.15-4.01]) and unfavorable cytogenetic risk (HR 1.81 [1.16-2.82]), whereas maintenance therapy (HR 0.53 [0.32-0.86]) and AlloHSCT (HR 0.40 [0.17-0.94]) were associated with better OS. CONCLUSIONS: This is the first multicenter report analyzing AML survival in Mexico. Challenges in this setting include a high induction-related mortality and low AlloHSCT rate, which should be addressed to improve outcomes.

Prevalence and Clinical Significance of FLT3 Mutation Status in Acute Myeloid Leukemia Patients: A Multicenter Study.

BACKGROUND AND AIMS: FLT3-ITD mutations in acute myeloid leukemia (AML) are associated with a poor prognosis. In Latin America, little epidemiological data exist about these mutations and their influence on clinical evolution and prognosis. Standardization and well-established clinical correlation make FLT3 mutational analysis by molecular methods an invaluable tool to decide among treatment options and to determine AML prognosis. METHODS: We assessed the prevalence of FLT3-ITD mutations in 138 patients with AML at four hematology referral centers from Mexico and Colombia. Molecular methods based on polymerase chain reaction (PCR) were employed for determining FLT3-ITD status. RESULTS: Mutations were present in 28 patients indicating a prevalence of 20.28%. Median age was 47 years (5-96). The FLT3 mutation positive group was older, had higher WBC and hemoglobin values and lower platelet counts but without statistical significance. A not previously described mutation in the FLT3 gene was found in one patient involving a nucleotide exchange of timine for cytosine at the 66608 position. A high mortality was found in the FLT3-mutated group, 67.8 vs. 42.72% in the non-mutated group and median survival was 4.9 months vs. 20.4 months, p = 0.009. A mutated FLT3 did not confer poor prognosis to those with M3 AML. The mutated FLT3 population had poor overall survival (OS) despite hematoprogenitor stem cell transplantation (HSCT). CONCLUSION: Prevalence of FLT3-ITD mutation in AML was present in a proportion comparable to other populations and, when present, was associated with a very poor prognosis.