EPIDEMIOLOGICAL AND MOLECULAR PROFILE OF PATIENTS WITH ACUTE MIELOID LEUKEMIA IN CEARÁ

Abstract

Acute myeloid leukemia (AML) is the second most common leukemia in adults and older patients represent most cases. The states of the Northeast of the country have stood out in the frequency of leukemia cases, and the frequencies are higher than the rate of 35% compared to other neoplasms, especially in the metropolitan regions of Fortaleza. In the State of Ceará, the number of cases of leukemia expected for the year 2020 is 6.17 cases/100,000 inhabitants in men and 4.29 cases/100,000 inhabitants in women. In view of this information, the aim of this study was to identify the molecular and epidemiological profile of patients with AML in the state of Ceará. Sample collection was performed in patients with AML treated at the General Hospital of Fortaleza, considered the main and largest hematology outpatient clinic in the metropolitan region of Fortaleza, as well as the State of Ceará. All patients participating in this study read and signed the informed consent form. Patients with other types of leukemias or other hematological diseases were excluded. This study was approved by the Research Ethics Committee of the Federal University of Ceará under protocol no. 38680520.9.0000.5054. From July 2021 to July 2022, 31 patients with AML were treated, of which 8 are women and 23 are men. The mean age observed was 50.4 years. 54.8% of patients live in the capital, while the other 45.2% of patients live in rural areas. Through immunophenotyping it was possible to verify that the main markers presented by LMA patients were CD33, CD13, CD117, CD45, MPO, CD34, CD64, HLA-DR, CD11c, CD11b e CD38. Thirteen patients (42%) had abnormal and complex karyotypes, of which six died. Five patients (16,1%) had the t(15;17)(q24;q21.3) corresponding to the PML-RARA fusion. Six patients (19,3%) had the FLT3 mutation that confers a poorer prognosis. During the clinical follow up, a total of 16 patients died due to septic shock, COVID-19, or refractoriness to treatment. The incidence of cases of adults over 50 years of age with AML was 58%, as it corroborates the expected incidence of cases regarding the age described in the literature. Studies indicate that immunophenotyping is critical to the differential diagnosis among AML subtypes. AML is defined by the mainly expression of the markers MPO, CD117, CD13, CD33, HLA-DR and CD38, corroborating what was observed in the results. In addition, depending on the alteration observed in the karyotype, it may confer poor or good prognosis to the patient. The PML-RARA merger, for example, is known as M3 AML or acute promyelocytic leukemia (APL), a subtype of AML with a better prognosis for patients. The FLT3 mutation is present in 1 in 3 patients with AML. The presence of this altered gene may mean a worse prognosis and a greater possibility of recurrence but allows a specific and differentiated treatment. Epidemiological data from this preliminary study indicate that in the state of Ceará AML is more common in male patients aged 50-80 years. In addition, the use of targeted therapies for patients with abnormal karyotypes as well as the adoption of stricter measures to prevent hospital infections may increase patient survival.