Comparison of Cryosurgery and Carbon Dioxide Laser Ablation for Treatment of Cervical Intraepithelial Neoplasia

Abstract

A group of 125 reproductive-age women with cervical intraepithelial neoplasia (CIN) were entered in a trial study comparing cryotherapy and CO2 laser ablation. Of these, 81 patients (39 treated with cryotherapy and 42 treated with laser) were available for evaluation at least one year after therapy and are the subject of this report. In all 81 patients, cytologic examination, colposcopy, and biopsies were used at the four-month follow-up visit to evaluate efficacy and the effects on healing of the two forms of treatment. Cytology, colposcopy, and, if indicated, biopsies were repeated at 8, 12, 18, and 24 months after treatment. Histologically confirmed success rates in the two groups were similar–about 90%. However, the two groups differed significantly with respect to healing. Patients in the cryotherapy group had significantly more frequent retraction of the proximal squamocolumnar junction into the endocervical canal than did patients in the laser group. In only 20 of the 39 patients (53%) treated with cryotherapy was colposcopy satisfactory, whereas in 36 of 42 patients (86%) treated with laser, colposcopic exam was judged satisfactory after healing. Although the relative recurrence rates are comparable for the two forms of treatment, CO2 laser therapy is preferable because of the greater frequency (p <.01) of satisfactory colposcopy that is possible during follow-up of patients with CIN. The CO2 laser and cryosurgery were found equally effective for treatment of cervical intraepithelial neoplasia. Satisfactory colposcopic examination could be accomplished significantly more frequently following laser treatment.