Persistence of human papillomavirus DNA in cervical lesions after treatment with diathermic large loop excision.

OBJECTIVE: The aim of this study was to identify human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions and to evaluate the persistence of viral DNA after diathermic large loop excision (DLLE) treatment. STUDY DESIGN: Biopsies from 36 patients with low- and high-grade CIN lesions were studied before and after DLLE treatment looking for HPV sequences. DNA was extracted to perform a radioactive polymerase chain reaction (PCR) using GP 5,6 generic primers. PCR products were analyzed by the single-stranded conformational polymorphism (SSCP) which is a simultaneous detection and typing method. Dot-blot hybridization with generic and type-specific biotinylated oligonucleotide probes was applied in some cases. RESULTS: HPV DNA was found in all pretreatment samples, and the viral type was identified in 80% of them, HPV 16 being the most prevalent. The viral type coincided with that detected in the first biopsy in all except one case. Seventy five percent of the patients (27 cases) were negative for CIN at follow up, but 50% of them remained HPV DNA positive. CONCLUSION: DLLE treatment was effective in removing the CIN lesion but not the HPV. This fact points out the need to asses the presence of HPV in DNA during the follow-up, since viral persistence has been considered a high risk factor for recurrence and/or malignant transformation.