Acute Lymphoblastic Leukemia (ALL) is the most common childhood cancer, accounting for 25% to 30% of pediatric neoplasms. The disease is characterized by chromosomal translocations and aneuploidies, genetic alterations that determine prognosis and treatment response. In the state of Pará, an estimated 360 new cases of leukemia are diagnosed annually, an incidence that may be influenced by regional genetic and environmental factors.

To investigate the potential influence of regional environmental factors on the distribution of gene fusions in patients diagnosed with ALL in the state of Pará between 2023 and 2025, considering the geographic origin of each case.

This study (Ethics Committee approval No. 4.040.805) analyzed patients with ALL diagnosed at the Octávio Lobo Children's Cancer Hospital (HOIOL) between 2023 and 2025. From blood samples, RNA was extracted, converted to cDNA, and used to detect five specific gene fusions (BCR::ABL, TCF3::PBX1, KMT2A::AFF1, ETV6::RUNX1, and SIL::TAL) via Nested PCR. The products were visualized by electrophoresis, confirmed by Sanger sequencing, and the data were descriptively analyzed using R Studio 12.1 Software.

Between 2023 and 2025, a survey at HOIOL identified 220 patients diagnosed with acute lymphoblastic leukemia (ALL). Of these, 56 had a detectable molecular biomarker, although residency data were available for only 41 of these patients. These patients were distributed across 22 municipalities in Pará and the city of Macapá, in Amapá. The most prevalent fusions were ETV6::RUNX1 (61% of cases) and TCF3::PBX1 (23% of cases). The city of Belém had the highest concentration of cases, with varied fusions: ETV6::RUNX1 (7), BCR::ABL (1), and TCF3::PBX1 (1). The municipalities of Ananindeua, Santo Antônio do Tauá, and São Félix do Xingu each presented cases of TCF3::PBX1 (1) and ETV6::RUNX1 (1), while Barcarena recorded BCR::ABL (1) and TCF3::PBX1 (1) fusions. Cases exclusively involving the ETV6::RUNX1 fusion were identified in Abaetetuba (2), Afuá (1), Ajuruteua (1), Canaã dos Carajás (1), Paragominas (1), Parauapebas (1), Porto de Moz (1), Viseu (1), and Macapá (4). In turn, single occurrences of the TCF3::PBX1 fusion were observed in Cametá (2), Bragança (1), Novo Repartimento (1), and Portel (1). Additionally, Capanema and Marabá each presented one case with the SIL::TAL fusion, and finally, the city of Moju recorded a single case with the KMT2A::AFF1 fusion.

Notably, the southeastern region of Pará (Parauapebas, Canaã dos Carajás, Marabá, Novo Repartimento, São Félix do Xingu), an area of intense mining activity, accounted for 17% of cases with poor-prognosis fusions. The recurrence of these alterations raises the hypothesis of an association with environmental exposure to heavy metals, although a direct causal relationship cannot be established. Similarly, the northeastern region of Pará (Abaetetuba, Moju, and Cametá), characterized by intensive agricultural activity, presented 9% of cases with poor-prognosis fusions, suggesting a possible link to pesticide exposure, though a causal link has not been proven. Belém, in turn, had the highest number of cases, predominantly of good prognosis, a fact that may be attributed to its large population and proximity to reference centers, which facilitates detection. The occurrence of severe leukemia in Pará, in mining and agribusiness areas, suggests a strong link with environmental factors and demands further investigation.