Post-Colposcopy Management and Progression Predictors of Biopsy-Proven CIN1 in Women Under 25 Years

The post-colposcopy management and outcome of cervical intraepithelial neoplasia grade 1 (CIN1) in women under 25 years of age was reviewed, and potential predictors for progression were identified.

Women under 25 with biopsy-proven CIN1 between January 1, 2010, and December 31, 2012 who were seen in the colposcopy clinic at the Queen Elizabeth II Hospital in Halifax, Nova Scotia were retrospectively reviewed. The regression, persistence, and progression rates of CIN1 were evaluated, and the relevant behavioural and biologic factors were reviewed.

Of the 326 women with a biopsy-proven CIN1, 234 (71.8%) women returned to the regular screening program, and 92 women remained in the colposcopy clinic during follow-up, with a median follow-up time of 26 months. Sixty-two percent of the women had no cervical abnormality, 23.6% of the women had persistent CIN1, and 14.4% of the women showed progression. Eight percent showed progression to CIN2 with a median time of 13 months, whereas 6.4% showed progression to CIN3+ within a median time of 17.5 months. The extent of the lesion (hazard ratio 2.33; 95% CI 1.17-4.64, P = 0.02) and the Pap test result at the initial visit (hazard ratio 2.16; 95% CI 1.22-3.82, P = 0.008) were significantly associated with progression to CIN2+.

On the basis of the 6% risk of CIN3+ and the median time to progression of 17.5 months, follow-up with cytology at 12 months seems acceptable. The extent of the lesion and the Pap test result at the initial visit were identified as risk factors for progression of CIN1.