Objective: To describe the natural history of cervical intraepithelial neoplasia (CIN) 2 in a prospective study of adolescents and young women, and to examine the behavioral and biologic factors associated with regression and progression.
Methods: Adolescents and women aged 13 to 24 years who were referred for abnormal cytology and were found to have CIN 2 on histology were evaluated at 4-month intervals. Risks for regression were defined as three consecutive negative cytology and histology visits, and progression to CIN 3 was estimated using Cox proportional hazards regression models.
Results: Ninety-five patients with a mean age of 20.4 years (±2.3) were entered into the analysis. Thirty-eight percent resolved by year 1, 63% resolved by year 2, and 68% resolved by year 3. Multivariable analysis found that recent Neisseria gonorrhoeae infection (hazard ratio 25.27; 95% confidence interval [CI] 3.11-205.42) and medroxyprogesterone acetate use (per month) (hazard ratio 1.02; 95% CI 1.003-1.04) were associated with regression. Factors associated with nonregression included combined hormonal contraception use (per month) (hazard ratio 0.85; 95% CI 0.75-0.97) and persistence of human papillomavirus (HPV) of any type (hazard ratio 0.40; 95% CI 0.22-0.72). Fifteen percent of patients showed progression by year 3. HPV 16/18 persistence (hazard ratio 25.27; 95% CI 2.65-241.2; P=.005) and HPV 16/18 status at last visit (hazard ratio 7.25; 95% CI 1.07-49.36; P<.05) were associated with progression Because of the small sample size, other covariates were not examined.
Conclusion: The high regression rate of CIN 2 supports clinical observation of this lesion in adolescents and young women.