Abstract
We have screened 78 genital tract tumours from Italian female patients for the presence of human papillomavirus type 16 (HPV-16) and HPV-18 DNA. Dot and Southern blot hybridization experiments revealed that DNA sequences of HPV-16 and/or HPV-18 are present in 66% of tumour samples. HPV-18 was detected in 80% of vulvar carcinomas. In these tumours the integration of HPV-18 DNA seems to occur in the E1/E2 region of the virus genome with long deletions in almost all samples. The invariable retention of the non-coding region and the E6/E7 open reading frames suggests that the integration event and the possible expression of these sequences could play a role in some stages of cellular transformation.