High-Grade Squamous Intraepithelial Lesions: Abbreviating Posttreatment Surveillance

Abstract

This retrospective study was conducted to evaluate the recommendation from the American College of Obstetrics and Gynecology that women who have been treated for cervical intraepithelial neoplasia (CIN) should be followed with cytology every 3 to 4 months for 1 year and once a year thereafter. All women who underwent loop excision for treatment of high-grade squamous intraepithelial lesions (n = 705) in the authors' dysplasia clinic between 1990 and 1999 served as study subjects. These patients were followed with cervical cytology every 3 to 4 months for 1 year and every 4 to 6 months during the second year. Of the 705 women treated for CIN 2 or 3 during the study period, 526 had at least 1 follow-up cervical smear performed within 2 years of treatment and were included in the analysis. Among the 546 study subjects, 456 (86.7%) had no further indication of dysplasia, and 70 (13.3%) had recurrent CIN 2 or 3 within 2 years of treatment. Fifty-one of these women had a follow-up cervical smear showing high-grade abnormality, which was confirmed histologically in 38 patients. The remaining 19 patients with recurrent CIN 2 or 3 were diagnosed by biopsy alone. Nearly three fourths (74%) of the recurrences were identified within the first 6 months after treatment. During the follow-up period, there were no cases of squamous cell carcinoma of the cervix in patients who underwent loop excision. Independent risk factors for recurrence were age and margin status of the surgical specimen. The average age of the women who had no further disease after treatment was 30 years compared with 36 years in those who had a recurrence (1.6-fold increase in risk of recurrence; 95% confidence interval, 1.29–1.9). Patients who had a negative margin on the pathology specimen had a decreased risk of recurrence (0.29-fold decrease; 95% confidence interval, 0.17–0.51). There was no significant difference in risk of recurrence associated with indeterminate margins, positive endocervical or ectocervical margins, or racial background. Kaplan-Meier analysis found that the probability of recurrence of high-grade disease was greatest in the first 6 months of follow up, least during months 7 to 21, and increased again in the 22nd, 23rd, and 24th months (P < 0.001).