A study of cryosurgery and the CO2 laser in treatment of carcinoma in situ (CIN III) of the uterine cervix.

The results of laser and cryosurgical treatment in 106 patients with histologically proven carcinoma in situ of the uterine cervix (CIN III) are presented. Seventy-one patients were treated with the laser and in 63 of these further follow-up with colposcopy and cytology failed to show any abnormality. This represents an initial success rate of 89%. In 8 patients (11%) initial treatment was considered to have failed because of persistent dyskaryotic smears and histological evidence of cervical intraepithelial neoplasia (CIN II-III). Six of these patients were treated successfully with a further laser application and two patients had conization. The overall success rate for the laser was 97%. Thirty-five patients were treated with cryosurgery and subsequent follow-up was negative in 29 of these patients (83%). The 6 treatment failures (17%) were subsequently successfully treated with local destructive therapy (4 with cryosurgery, 1 with laser, and 1 with needle diathermy). The overall success rate for cryofreezing was 94.2%. In cases of CIN III the laser is more likely to achieve eradication of the lesion with a single application than cryofreezing.