Inconclusive role of human papillomavirus infection in breast cancer

BACKGROUND: Epidemiological studies have examined the association between human papillomavirus (HPV) and breast cancer, but the findings are inconclusive. This study aimed to detect the prevalence of HPV in breast cancer tissue in patients from northeastern China and define the association between HPV and breast cancer using meta-analysis. METHODS: Polymerase chain reaction (PCR) was used to test cutaneous or mucosal HPV DNA sequence in 77 breast cancer samples and 77 corresponding adjacent normal tissues. The prevalence of HPV in breast cancer was estimated by pooling data from 38 studies. A meta-analysis of 16 case–control studies was conducted to investigate the association between HPV and breast cancer. RESULTS: We did not find HPV DNA sequence in any of the 154 tissue specimens we tested. However, our meta-analysis revealed a HPV prevalence of 30.30 % (95 % confidence interval [CI] = 22.30–38.40 %) among breast cancer cases; most of these involved high-risk HPV types (35.50 %, 95 % CI = 25.00–46.10 %). HPV prevalence in breast cancer varied by geographic region, publication period, and PCR detection method. An increased risk of breast cancer was observed in association with exposure to HPV (odds ratio [OR] = 3.24, 95 % CI = 1.59–6.57), which was influenced by geographic region, HPV DNA source, PCR primer used, and publication period. CONCLUSIONS: HPV, especially high-risk HPV types, may be associated with an increased risk of breast cancer, and this association varies dramatically among geographic regions.