Meta-analysis of the effectiveness of cryotherapy in the treatment of cervical intraepithelial neoplasia

BackgroundCryotherapy can be used for the ablation of cervical intraepithelial neoplasia (CIN).ObjectivesTo provide an updated and comprehensive estimate of the efficacy of cryotherapy for CIN.Search strategyA literature search identified original studies (randomized controlled trials and clinical reports).Selection criteriaStudies reporting cure rates, acceptability, and safety of cryotherapy were included in the analysis.Data collection and analysisNumber of persistent or recurrent lesions at follow-up, adverse events, and complications were recorded. Quality of the methodology was also assessed. Meta-analyses were performed according to CIN thresholds, geographic region, study year, setting, study design, presence of endocervical involvement, freezing method, duration of follow-up, and status of the cryotherapy provider.Main resultsA total of 146 articles were retrieved; 77 papers—equivalent to 28 827 cases of treated CIN—were included in the meta-analysis. Cryotherapy achieved cure rates of 94.0% (CIN1), 92.0% (CIN2), and 85.0% (CIN3). Use of the double-freeze method and absence of endocervical involvement significantly increased cure rates. Minimal complications were reported as adverse effects.ConclusionsCryotherapy is an effective, safe, and acceptable treatment for CIN. It has been shown to be successful in low-resource settings, enabling availability and accessibility of early detection services.