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

BACKGROUND: Cryotherapy can be used for the ablation of cervical intraepithelial neoplasia (CIN).

OBJECTIVES: To provide an updated and comprehensive estimate of the efficacy of cryotherapy for CIN.

SEARCH STRATEGY: A literature search identified original studies (randomized controlled trials and clinical reports).

SELECTION CRITERIA: Studies reporting cure rates, acceptability, and safety of cryotherapy were included in the analysis.

DATA COLLECTION AND ANALYSIS: Number 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 RESULTS: A 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.

CONCLUSIONS: Cryotherapy 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.