Treatment failure following large loop excision of the transformation zone for the treatment of cervical intraepithelial neoplasia at Rajavithi Hospital.

OBJECTIVE To evaluate the treatment failure rate of large loop excision of the transformation zone (LLETZ) in the treatment of cervical intraepithelial neoplasia (CIN) and the risk of persistence or recurrence depending on the clinicopathologic factors. MATERIAL AND METHOD Retrospective case-record review of 250 women who had a final diagnosis of CIN and underwent LLETZ in Rajavithi Hospitalfrom June 1st, 1998 to December 31st, 2003. Computerized files of these patients were then reviewed for clinicopathological follow-up results. RESULTS Success rate of 86.8% was obtained. The incidence of treatment failure was 13.2%. The clinicopathologic factor associated with the persistence or recurrence was the presence of CIN at the margin of excision. Of 69 cases with incomplete excision (positive margin), treatment failure developed in 29.0%, compared to 5.2% in patients with complete excision (negative margins) (p < 0.001). Using multivariate analysis, incomplete excision and endocervical margin involvement of specimen were independent risk factors for the treatment failure of CIN. CONCLUSION LLETZ is an effective treatment for CIN. Treatment failure rate is low. Positive surgical margin is a predictor of persistence or recurrence after LLETZ. Incomplete excision and endocervical margin involvement of specimen are significant independent risk factors.