Human Papillomavirus Infection after Treatment for High-grade Cervical Intraepithelial Neoplasia

Cervical carcinoma is a leading cause of mortality from cancer among women worldwide. Oncogenic types of human papillomavirus (HPV) are recognised as causative agents of cervical cancer and its precursor, cervical intraepithelial neoplasia (CIN). It was shown that successful treatment of CIN results in clearance of HPV infection and treatment failure is accompanied by the detection of viral persistence. Therefore, follow-up testing for HPV of CIN treated patients is now accepted as an option for monitoring for recurrent disease. The aim of this study was to investigate the prevalence of high risk HPV after treatment of Bulgarian women for high-grade CIN. Cervical specimens were obtained from 59 women treated for CIN by conization. They were subjected to Pap smear test and HPV DNA testing by PCR. Cytological abnormalities were found in 18.6% of all women. HPV DNA was detected in 91% of women with abnormal cytology. Only 8.3% of women with normal cytology were HPV positive. HPV genotyping showed that the most prevalent HPV type was HPV16 accounting for 80% of HPV positive samples with abnormal cytology and for 25% of HPV positive samples with normal cytology. HPV18 was detected only in one specimen with abnormal cytology. HPV31 was found in 50% of all HPV positive materials. We were not able to detect HPV33. Our study indicates that the posttreatment high risk HPV infection detected in Bulgarian women is a risk factor for subsequent cervical dysplasia and that the high risk HPV testing after conization is important for predicting the risk of disease recurrence.