Background: Forkhead box P3 (FOXP3 ) is a key gene in the immune system which also plays a role in tumor development. This study aims to explore the association of two FOXP3  polymorphisms (rs3761548 and rs3761549) with susceptibility to breast cancer (BC).
Method: A case–control study was conducted, involving 560 patients and 583 healthy individuals from the Chinese Han population. The genotypes of FOXP3  polymorphisms were detected using the Sequenom MassARRAY method. The association between FOXP3  polymorphisms and BC risk was evaluated using a χ ² test with an odds ratio (OR) and 95% confidence intervals (95% CIs) under six genetic models. False-positive report probability was utilized to examine whether the significant findings were noteworthy.
Results: We observed that rs3761548 was associated with a higher BC risk in heterozygous, dominant, overdominant, and allele genetic models (CA vs CC: OR =1.32, P =0.031; CA/AA vs CC: OR =1.32, P =0.023; CA vs CC/AA: OR =1.29, P =0.042; A vs C: OR =1.26, P =0.029), whereas no significant association was found between rs3761549 and BC risk. In addition, CA, CA/AA genotype, and A allele of rs3761548 were related to larger tumor size, and the A allele was also correlated with a positive status of Her-2 in BC patients.
Conclusion: Our study suggests that FOXP3  polymorphism rs3761548 is associated with BC susceptibility in the Chinese and may be involved in tumor progression. Future studies are needed to confirm the results in a larger population with more races.
Keywords: forkhead box P3, polymorphism, breast cancer, risk