Increased detection of HPV 16 virus in invasive, but not in early cervical cancers

Human papilloma virus type 16 (HPV 16) DNA is found in about 50% of cervical squamous cell carcinomas (SCCs), and this association has raised the possibility of a causal role for HPV 16 in cervical carcinogenesis. We have tested this hypothesis by assaying a series of biopsies (n = 119) ranging from normal mucosa to infiltrating SCC with the PCR-technique for the presence of HPV 16 DNA. While HPV 16 DNA was detected in 50% of our cases with invasive SCC, the incidence of HPV 16-positive samples was about 10% in all other biopsies ranging from normal mucosa to cases of carcinoma in situ. HPV 16 therefore appears to be involved in late tumor promotion but not in early tumor development.