Utility of Human Papillomavirus Genotyping in the Management of Low-Grade Squamous Intraepithelial Lesions.

OBJECTIVE: The aim of the study was to determine the usefulness of human papillomavirus (HPV) partial genotyping test in the triage of newly diagnosed low-grade squamous intraepithelial lesions (LSILs). MATERIALS AND METHODS: We analyzed 143 patients with LSIL diagnosed de novo. Lesions were classified as positive for HPV 16 or HPV 18, positive for HPV but not HPV 16 or HPV 18 (HPVno16no18) or no HPV detected (HPVneg). Patients were followed for a period of 2 years or until the lesion progressed. We calculated absolute and relative risks for progression and regression according to the HPV result. RESULTS: The mean (SD) age was 33.8 (11.1) years. A total of 19.6% were positive for HPV 16, 4.9% for HPV 18, and 63.6% for HPVno16no18. The absolute risk of HPV 16 for progression to cervical intraepithelial neoplasia grade 2 or more (CIN 2+) was 32.1%, 14.3% for HPV 18, and 5.8% for HPVno16no18. None of the HPVneg cases evolved to CIN 2+. The presence of HPV 16 conferred a 7.4 (95% CI = 2.7-20.3) times greater risk of developing CIN 2+ than its absence. The absolute risks for HPV 16, HPV 18, HPVno16no18, and HPVneg for regression were 53.6%, 57.1%, 75.4%, and 87.5%, respectively. Relative risks for regression were 0.7 (95% CI = 0.5-0.9) for HPV 16 and 1.3 (95% CI = 1.1-1.5) for HPVneg. CONCLUSIONS: The HPV 16 LSILs are more likely to progress to CIN 2+, so tight control and immediate colposcopy are crucial, whereas when HPV 16 is not present, follow-up could be less strict. Low-grade squamous intraepithelial lesions in which high-risk HPV is not detected do not progress to CIN 2+, so its control should be different from other LSIL, and conservative management could be an acceptable strategy.