Evidence for an association of human papillomavirus and breast carcinomas

Human papillomavirus (HPV) DNA has been detected in breast carcinoma by different laboratorial techniques, suggesting the virus could play a role in the pathogenesis of this tumor. The aim of the present study is to investigate the presence of HPV in patients with breast carcinoma and the correlation of the viral infection with prognostic factors for the disease outcome. Between June 2001 and July 2002, 101 paraffin embedded breast carcinoma specimens were analyzed through polymerase chain reaction (PCR) and sequencing of HPV-E6 gene. Twenty specimens of reduction mammoplasty and 21 specimens of fibroadenomas were also studied as a non-malignant control group. Two different specific primer sets targeting E6 region of the HPVs 16 and 18 were used for the analysis. The HPV DNA was detected in 25 breast carcinomas (24.75%), but in none of the benign breast specimens (p< 0.001). Out of the 25 positive cases, 14 were HPV-16 positive (56%) and 10 were HPV-18 positive (40%). An original finding was the detection of both HPV-16 and - 18 in a single tumor (4%). The amplified viral sequences confirmed the presence of HPV-16 and - 18. No correlation between the presence of HPV DNA and specific prognostic predictors for the disease outcome was observed. Our results suggest that the presence in the breast of either HPV-16 or - 18 might be related to development of the malignant phenotype. Further studies are warranted.