Background: The study aimed to examine the association between human leukocyte antigen (HLA) class II allele frequencies and breast cancer in Iranian women.
Methods: A total of 100 patients with pathologically proven breast cancer who referred to Cancer Institute were randomly selected and compared with a group of age matched healthy blood donors (n = 80). HLA class II alleles were determined by amplification of DNA followed by HLA-typing using sequence-specific primer (SSP) for each allele.
Results: The frequency of HLA-DQA1*0301 (P=0.001, OR=3.4) and HLA-DRB1*1303 (P=0.02, OR=2.3) among breast cancer patients was significantly higher than those in control group. HLA-DQA1*0505 (P=0.003, OR=0.4), HLA-DRB1*1301 (P=0.002, OR=0.12) and HLA-DQA1*0101 (P=0.01, OR=0.21) alleles showed negative association with breast cancer.
Conclusion: The findings suggest that HLA-DQA1*0301 allele is mainly associated with increased risk of breast cancer in Iranian female patients. HLA-DQA1*0505 and HLA-DRB1*1301 alleles are suggested as protective genetic factors against breast cancer. The findings confirm that specific alleles of HLA class II influence breast cancer risk.