Comparing Cervical Cytology and Histology Among Human Papillomavirus-Vaccinated and -Unvaccinated Women in an Academic Colposcopy Clinic.

OBJECTIVE To analyze differences in cytology and histology results between patients previously vaccinated against human papillomavirus (HPV) compared with unvaccinated patients who presented to an academic colposcopy clinic for evaluation of abnormal cervical cytology. METHODS Using data from a patient registry from 2007 to 2014, we examined 1,662 patients aged 26 years or younger at the time of presentation. Demographics, HPV vaccination status, smoking, pregnancy history, sexually transmitted infections, number of sexual partners, contraception, immunosuppression, and other relevant medical issues were reviewed. Cytology and histology results were compared between previously HPV-vaccinated and unvaccinated women to determine if there was a difference in the severity of subsequent cytologic or pathologic specimens. RESULTS In multivariable analyses, women who previously received at least one dose of the HPV vaccine had 53% (adjusted odds ratio [OR] 0.47, 95% confidence interval [CI] 0.34-0.66; P<.001) lower odds of presenting with high-grade cytology (adenocarcinoma in situ, atypical glandular cells, atypical squamous cells cannot rule out high grade, and high-grade squamous intraepithelial lesion) and 36% (adjusted OR 0.64, 95% CI 0.48-0.85; P=.002) lower odds of presenting with cervical intraepithelial neoplasia 2 or 3 or worse histology compared with unvaccinated women. CONCLUSION Patients presenting for colposcopic evaluation of abnormal cytology who had previously received the HPV vaccine had fewer high-grade lesions on both cytology and histology when compared with HPV-unvaccinated women. LEVEL OF EVIDENCE II.