Factors associated with progression of cervical human papillomavirus (HPV) infections into carcinoma in situ during a long-term prospective follow-up.

In the course of a prospective study of 508 women with papillomavirus (HPV) lesions of the uterine cervix, 66 lesions that progressed into carcinoma in situ (CIS) were identified and treated by conization during a mean follow-up period of 35 months. The lesions were investigated with light microscopy and with in-situ DNA hybridization using 35S-labelled probes for HPV 6, 11, 16, 18, 31 and 33. After radical cone treatment, 11 of the 66 women (16.7%) have presented with a recurrent HPV infection. The recurrence rate increased with the duration of the follow-up period from less than 10% at the mean follow-up of 25 months to 16.7% at the most recent follow-up at 35 months. Most of these 66 HPV lesions (89%) presented with concomitant CIN in the first punch biopsy, but it is noteworthy that the other 11% presented without concomitant CIN. HPV DNA of at least one of the six types examined was found in 73% of the first biopsies and it is noteworthy that the so-called 'low-risk' types, HPV 6 and 11, were found as frequently as the 'high-risk' types, HPV 16 and 18 (18% and 17%, respectively). This would suggest a similarity in the biological behaviour of these two HPV groups. Although the concept of the 'high-risk' and 'low-risk' HPV types may remain at least partially valid, it is imperative to realize that infection by HPV 6 and 11 by no means excludes the possibility for clinical progression into CIS and eventually to an invasive carcinoma.