LAUSR

OBJECTIVE Analyze long-term (20 years) cytology and histology outcomes after treatment of high-grade cervical intraepithelial neoplasia (HGCIN) with thermal ablation (TA). METHODS All women having TA for HGCIN between January 1996 and December 1998 (36 months; N = 885) were identified; data were collected on age of patients, symptoms, colposcopy findings, and biopsy reports. Local and national (cytology and colposcopy) databases and colposcopy records were used to collect long-term follow-up data. Probability of CIN recurrence was assessed using Kaplan-Meier "survival" curve. RESULTS Follow-up data (available for 796) was collected in 2018 capturing 20 years of follow-up data. Two hundred eighty-one women were treated for CIN 2 and 515 women for CIN 3. Seven hundred ninety-one of 796 (>99%) were treated at first visit. Two hundred sixty two of 796 (33%) had evidence of crypt involvement on pretreatment biopsy. Probability of having consistently normal cytological follow-up was 92%, 89%, 86%, and 83% at 5, 10, 15, and 20 years, respectively. Cumulative probability of having recurrent HGCIN was 0.5% at 5 years, 1% at 10 years, 1.9% at 15 years, and 3% at 18 years. There was 1 invasive squamous cell cancer at 11 years after treatment. CONCLUSIONS Thermal ablation is a safe and effective treatment for HGCIN, which is now shown to have stood the test of time. We advise more widespread adoption in the United Kingdom and globally so long as agreed criteria are met.