Breast Cancer Is Associated with Increased HLA-DRB1*11:01 and HLA-DRB1*10:01 Allele Frequency in a Population of Patients from Central Italy.

The relationship between HLA-DRB1 allele polymorphism and breast cancer (BC) development is still unclear and needs further investigation. To address this issue, we analyzed HLA-DRB1 allele frequency (AF) by sequence-based typing (SBT) in 47 patients from central Italy with BC and 156 sex and age-matched healthy controls. Two hundred ninety-seven individuals from the same region were utilized as historical controls. Pearson's chi-square analysis with Yate's correction or Fisher's Exact test with Bonferroni's correction, as appropriate, were used to compare HLA-DRB1 AF differences in patients and controls. A total of 36 HLA-DRB1 alleles were identified. A detailed study showed that HLA-DRB111:01 and HLA-DRB110:01 alleles are significantly associated with increased BC risk. In particular, HLA-DRB111:01 AF was significantly higher in patients with BC than in healthy females and historical controls, even following Bonferroni's correction (stage I-II BC patients vs historical controls p<0.00; stage III-IV BC patients vs female healthy controls p=0.025 and historical controls p<0.00). The HLA-DRB110:01 allele was also positively associated with BC as evidenced by a significantly higher AF in patients with BC than in healthy controls (BC patients stage I-II vs historical controls corrected p =0.01). These results suggest that both HLA-DRB111:01 and HLA-DRB110:01 AF could represent interesting markers in patients at risk of developing BC.