Long-term follow-up of cervical intraepithelial neoplasia treated with minimal conization by carbon dioxide laser

Minimal conization with carbon dioxide laser (CO2) for safe diagnosis and treatment of cervical intraepithelial neoplasia (CIN) 1-3 has been utilized for 15 years. To evaluate the results of 15 years' follow-up.

Clinical prospective study: 2,903 non-pregnant women whose cervicovaginal smear revealed CIN 1-3, confirmed by colposcopy, were referred for minimal conization treatment (LMC). This outpatient free-hand excision is performed under local anesthesia with a 60-W continuous laser beam focused to a 0.1-mm spot size, giving a power density of 165,000 W/cm2. Adjuvant cervical curettage is done routinely.

Complications after the procedure were insignificant. Histopathological investigations revealed invasive carcinoma in 1.2% of the minicones. The primary cure rate was 96.1%. In the life table analysis of the patients the cumulative risk of recurrence for all forms of CIN was 0.89% at year 5, 1.36% at year 10, and 3.02% at year 15. There was no sudden onset carcinoma during the follow-up period.

Minimal conization is a safe, effective treatment for CIN and early forms of microinvasive carcinoma. Invasive carcinoma can be detected early and should be treated without delay. The cumulative risk of developing new CIN is 3.02% at year 15 and there is no risk of sudden-onset invasive carcinoma following this procedure.