Identification and characterization of human papillomavirus DNA sequences in Italian breast cancer patients by PCR and line probe assay reverse hybridization.

Human papillomavirus (HPV) infection is known to play a fundamental role in cervical and other ano-genital human cancers. The recent identification of HPVs in human breast tumors and the immortalization of normal breast cancer cells by HPV high risk types 16 and 18 suggest that the virus could be implicated in the pathogenesis of human mammary tumors. In this study, we investigated the presence of high and low risk HPV genotypes in 30 human breast cancers of different histotypes by PCR with specific HPV primers (MY09/MY11 and GP5+/GP6+) and by line probe assay (LiPA) reverse hybridization. Since the only positive case (untypable HPVX+) was a papillary breast carcinoma, a rare tumor variant, we analyzed a further cohort of 32 papillary cancers and found one additional HPV DNA-positive case (HPV66+). Our results suggest that HPV infection is not significant in mammary tumorigenesis, with the exception of particular tumor histotypes, such as papillary cancer.