Follow up after LLETZ: could schedules be modified according to risk of recurrence?

Objectives To document the pattern of recurrence of disease following large loop excision of the transformation zone (LLETZ) to identify a low risk group of women who might benefit from less intensive cytological surveillance. Design Analysis of prospectively collected information with retrospective review of follow up smears. Population Three thousand, five hundred and sixty women who underwent LLETZ (median age 31 years; IQR 12 years). Setting Colposcopy clinic at Northern Gynaecological Oncology Centre, Gateshead. Methods Women treated with LLETZ from 1988 to 1995 were reviewed. Information on the pathology from LLETZ was collected prospectively and information on the subsequent smears was obtained from the family health authorities. Results Invasive cancer was detected on the original LLETZ in 134 women who were excluded from the study. Of the remaining 3426 women, histology of LLETZ showed high grade CIN (II and III) in 2371 (69%). At least one follow up smear was undertaken in 3385 women (99%). This constituted 9765 women years of follow up with a mean duration of 35 months. Four hundred and seventeen women (12.2%) had a dyskaryotic follow up smear. Incomplete excision of the lesion and an age of ≥ 50 years at the time of the LLETZ were associated with an increased risk of recurrent CIN. Based on these risk factors the study group was divided into three risk groups: 1. women aged < 50 with no disease at the margins (n=1680); 2. women aged ≥ 50 with disease at the margins (n=93); and 3. women aged < 50 with positive margins, or aged ≥ 50 with negative margins (n=1653). The cumulative survival without recurrent CIN at five years for these groups were 92%, 57% and 86%, respectively. Conclusion Women aged ≥ 50 with CIN at the margins of excision constituted a small minority high risk group (3%). Consideration should be given to repeat treatment of these women rather than surveillance. Women aged < 50 with complete excision of low grade CIN comprised 51% of the study group. These women were at low risk of recurrent CIN and might benefit from less intensive cytological surveillance following LLETZ.