Background: Breast cancer is a major cause of female death worldwide. Several factors contribute to cancer development, one of the most important of which is viruses identified by the host immune system and Toll-like receptors (TLRs). Human herpes virus 8 (HHV-8) is one of the viruses with a proven role in Kaposi’s sarcoma development. Objectives: This study aimed to investigate the correlation between HHV-8 infection and breast cancer, as well as the role of rs4986791 polymorphism in women’s health. Methods: Blood samples of 80 healthy subjects and 80 patients suffering from breast cancer were collected (from May-September 2018). The presence of HHV-8 in the samples was examined by PCR. Also, the rs4986791 polymorphism was evaluated by nested PCRRFLP. Results: The results showed a significant relationship between age and breast cancer. Of 80 cancer patients and 80 healthy subjects, 17 (21.3%) and 15 (18.8%) were carriers of HHV-8, respectively. Also, there was no significant relationship between HHV-8 infection and breast cancer (P = 0.693). We found no significant relationship between the presence of virus and cancer grade (P = 0.618). Conclusions: The results of rs498679 polymorphism analysis indicated that the T allele was associated with increased health phenotype and decreased risk of cancer development. Also,womenwith TT genotype exhibited significantly lower HHV-8 infection than the other genotypes.
