Objective: To assess the rate, the cumulative proportion, and the predictors of cervical intraepithelial neoplasia grades 2-3 (CIN 2-3) and invasive disease during the follow-up of patients conservatively treated for microinvasive (stage Ia1-2) squamous cell carcinoma (MIC) of the uterine cervix.

Methods: Two hundred thirty women (median age, 37 years; range, 20-69 years) conservatively treated for MIC were followed up for 10 years and analyzed for cumulative proportion of CIN 2-3/invasive disease. The multivariate survival analysis was used to assess the clinicopathological features predicting the development of CIN 2-3/SCC.

Results: Of the 230 patients primarily treated by cone, 76 (33%) underwent hysterectomy as the immediate retreatment, and 13 had a residual disease. The remaining 154 women were subjected to posttreatment follow-up. The depth of stromal invasion was strongly associated with the prevalence of positive lymph nodes and lymphovascular space invasion (LVSI). The detection rate of CIN 2-3/SCC was stable at the first 2 visits (6.5% and 6.9%) and dropped thereafter. The cumulative proportion of patients whose conditions were diagnosed as CIN 2-3/carcinoma was 0.07, 0.09, 0.15, and 0.19 at 6, 12, 36, and 120 months, respectively. In multivariate survival analysis, involvement of 4 quadrants (odds ratio [OR], 5.8), LVSI (OR, 4.5), and cone margin involvement (OR, 5.6) were significant independent predictors of CIN 2-3/SCC after treatment. The upper age tertile (42-69 years) was an independent protective factor (OR, 0.3; 95% confidence interval, 0.1-0.9).

Conclusions: A close, long-term surveillance should be scheduled for the MIC patients conservatively treated. Cone margin involvement, LVSI, and the number of quadrants involved on colposcopy are independent risk factors for disease persistence and/or progression to SCC.