RESUMEN
BACKGROUND: The optimal management strategy for women with low-grade biopsy-proven cervical intraepithelial neoplasia (CIN) is not clear. Our objective was to compare the effectiveness of regular colposcopic follow-up and treatment of progressive disease only versus immediate treatment. METHODS: Data were accrued between November 2000 and March 2006 for a noninferiority randomized clinical trial of 415 women with biopsy-proven grade 1 CIN from 8 Canadian and 2 Brazilian colposcopy clinics. Subjects were randomly assigned to either undergo immediate treatment with a loop electrical excision procedure (LEEP) or receive regular colposcopic follow-up for 18 months. The primary outcome was progression of disease to CIN 2 to 3 was based on histology obtained during 18 months of follow-up. Treatments were compared using differences of proportion with a 9% noninferiority margin. Analysis was conducted on the basis of intention-to-treat. RESULTS: An initial LEEP was performed on 179 women. Disease progression was found in 32. Easily controlled vaginal bleeding occurred in 16 (8.9%). During follow-up, disease progression was identified in 3 (1.7%) women in the immediate treatment arm and 9 (4.4%) in the colposcopic follow-up arm-a tolerable difference of 2.7% with 1-sided 95% confidence interval (CI) upper limit of 6.0%. Compliance with all 3 follow-up visits was 61% overall, but significantly worse in women ≤30 years of age (P < .05). CONCLUSIONS: The risk of progression to CIN grade 2 or 3 or cancer over 18 months was similar in the 2 treatment groups. In Canada and Brazil, follow-up for 18 months is a reasonable management strategy for women with persistent low-grade cytology who are found to have grade 1 CIN on referral for colposcopy and cervical biopsy.