Efficacy, safety and tolerability of green tea catechins in the treatment of external anogenital warts: a systematic review and meta-analysis

Background External anogenital warts (EGWs) are non-malignant skin tumours caused by human papillomavirus. They are one of the fastest growing sexually transmitted diseases. Current treatments are unsatisfactory. Green tea sinecatechin Polyphenon E ointment is a botanical extract from green tea leaves exhibiting anti-oxidant, anti-viral and anti-tumour properties. Objective The aim of this study was to integrate valid information and provide basis for rational decision making regarding efficacy and safety of green tea extracts in the treatment of EGWs. Methods A systematic search in electronic databases was conducted using specific key terms. Main search was performed independently by two reviewers. The accumulated relevant literature was subsequently systematically reviewed and a meta-analysis was conducted. Results Three randomized, double-blind, placebo-controlled studies evaluating efficacy and safety of Polyphenon E 15% and 10% in the treatment of warts were included in the systematic review and meta-analysis. A total of 660 men and 587 women were enrolled. Regarding primary outcome, both Polyphenon E 15% and 10% demonstrated significantly higher likelihood of complete clearance of baseline and baseline and new warts compared with controls. No significant heterogeneity was detected. Recurrence rates were very low. Commonest local skin sign was erythema and local skin symptom was itching. Conclusions Efficacy of Polyphenon 15% and 10%, at least for the primary endpoint, is clearly indicated. Polyphenon E treatment exhibits very low recurrence rates and appears to have a rather favourable safety and tolerability profile. Recommendations for future studies should include evaluation of the efficacy of green tea catechins in the treatment of internal anogenital warts and direct comparison with its principal comparator, imiquimod.