Recurrence of cervical intraepithelial neoplasia (CIN) is diagnosed in up to 6 percent of women following loop excision even if the excision margins are histologically clear. The risk factors for recurrence are poorly defined, which has lead to uncertainty about optimal follow-up. Paraskevaidis and colleagues studied more than 600 women following successful loop excision of CIN to identify risk factors and clarify recommendations for follow-up.

The women in this study were treated at a university hospital in Greece for CIN and had histologic clear margins following loop excision. All patients were followed with cytology and colposcopy at four, eight and 12 months and then annually.

In women with recurrent lesions, specimens were reviewed by a pathologist who had no knowledge of the original results. The 31 women who developed subsequent CIN were compared with the 604 women in whom no subsequent lesions were found, with special attention given to age, smoking, grade of initial lesion, evidence of glandular involvement and presence of satellite lesions.

The mean duration of follow-up was more than five years. All but one of the subsequent lesions developed during the first year, and in 29 of these cases at least one Papanicolaou test was abnormal. Women who developed subsequent lesions were significantly older than those who did not and were more likely to have had glandular involvement or satellite lesions with the initial lesion. Smoking and grade of initial lesion were not associated with development of subsequent CIN. Statistical analysis confirmed age older than 40, glandular involvement and presence of satellite lesions as independent risk factors for development of lesions during follow-up. All three risk factors were present in 45.1 percent of women who developed CIN following loop excision. In addition, 38.7 percent of women had two risk factors and 9.7 percent had one.

The authors conclude that the overall risk of CIN in women with clear margins following loop excision is around 5 percent, and most cases present within the first year following surgery. Because this incidence is lower than that of the general population, most women could return to normal screening if cytology remains negative at one year. More intensive follow-up may be indicated for women with the risk factors identified in this study.