The incidence of HPV in a Swedish series of invasive cervical carcinoma.

The incidence of HPV was studied in 71 invasive squamous carcinomas of the cervix using PCR technique. We used primers, which presumably recognize all types of HPV (consensus primers), and also type-specific primers. In situ hybridization was carried out in 24 of the cases. The overall incidence of HPV was 53/71 (75%) of which 5 cases were positive with the consensus primers only. However, 21/71 cases (30%) were negative for the consensus primers but positive for one of the type-specific primer pairs. This finding indicates that subgenomic deletions may have occurred in the viral genome upon integration in the human DNA. In situ hybridization was positive in 14/24 cases (58%), showing excellent correlation with PCR results. The HPV types detected were, in descending order of frequency: type 16 (52%), 31 (23%), 18 (13%), 33 (12%). No cases of HPV type 6 or 11 were found in this series of invasive carcinomas.