Laser or cryotherapy for cervical intraepithelial neoplasia: a randomized study to compare efficacy and side effects.

A randomized study was performed to compare efficacy and side effects of laser and cryotherapy: 51 patients were treated with laser vaporization and 50 patients with cryotherapy. Success rates for laser and cryotherapy were not significantly different. Success rates were significantly related to lesion size. Grade of CIN, positive endocervical curettage, parity, and age at treatment were not found to be related. Vaginal discharge, both in duration and amount, was significantly less in patients treated with laser vaporization, compared with cryotherapy, but pain and bleeding occurred more often in patients treated with laser vaporization. A brief review of possible sources of bias in comparative studies on laser and cryotherapy is given, indicating the preference for a randomized study. It is concluded that widespread introduction of laser facilities in smaller centers is not justified, because the success rates are not better than those of cryotherapy, and because the advantages of less discharge are outweighed by the high cost.