GSTM1-null polymorphism and cancer association in the brazilian population
A partir d'une revue systématique de la littérature publiée jusqu'en décembre 2025 (9 études, 3 368 personnes), cette étude analyse la fréquence du polymorphisme GSTM1-null dans la population brésilienne et estime le risque de cancer associé en fonction de l'origine ethnique
PURPOSE: The GSTM1-null polymorphism is associated with altered detoxification and increased cancer susceptibility. Brazil’s highly admixed population is unique for investigating ethnic variation in genetic risk factors. We aimed to investigate the frequency of GSTM1-null genetic polymorphism in the Brazilian population and explore cancer associations.
METHODS. A systematic review was conducted following PRISMA-P guidelines. PubMed, LILACS, and Medline were searched through December 2025 without restrictions. Studies reporting GSTM1-null frequencies stratified by self-reported skin color or ethnic background in Brazil were included. Methodological quality was assessed using STROBE criteria by two independent reviewers. Prevalence estimates were synthesized by geographic region and ethnic group. Associations between GSTM1-null genotype and cancer outcomes were evaluated across case-control studies.
RESULTS: Nine cross-sectional studies included 3,368 individuals (white=1,834; brown=789; black=590; Amerindian=155). The overall GSTM1-null frequency was 44.9%, highest among whites (51.1%), followed by browns (38.4%), Amerindians (34.8%), and blacks (33.4%). In Southeastern Brazil, prevalence was higher among whites (53.6%) compared to browns (41.6%) and blacks (29.6%). Ten case-control studies showed significant associations between GSTM1-null and cancer risk, including in black individuals (OR=2.72; 95% CI: 1.44–5.17), solid tumors in whites (OR=1.55; 1.21–1.98), gastric cancer in whites (OR=4.44;2.49–7.92), and osteosarcoma in browns (OR=3.50;1.04–11.77). Associations were also observed for chronic myeloid leukemia (OR=0.61;0.21–0.77) and lung cancer (OR=1.96;1.01–3.78).
CONCLUSION: Substantial ethnic variation in GSTM1-null prevalence exists in Brazil and is associated with differential cancer risk. These findings highlight the importance of genetic heterogeneity and support further investigation into gene–environment interactions in admixed populations.
Annals of Epidemiology , article en libre accès, 2026