Efficacy of cryotherapy for oral leukoplakia: A systematic review

Oral leukoplakia (OL) is the most common oral potentially malignant disorder and carries a risk of malignant transformation. Cryotherapy is a minimally invasive treatment option for OL, but its efficacy and optimal dose-response remain inconsistent among various studies. This systematic review evaluated the clinical efficacy and safety of cryotherapy for OL lesions and explored whether the characteristics of the lesions and treatment parameters influenced clinical outcomes. Electronic searches were performed in Embase, PubMed, and the Cochrane Central Register of Controlled Trials according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Seven studies reporting original clinical outcomes of cryotherapy for OL lesions were included. Data on cryotherapy dose, number and frequency of sessions, complete regression rates, and recurrence rates were extracted. Seven studies comprised 357 patients and approximately 360 OL lesions. Complete regression rates ranged from 77.8% to 100%. Cryogun cryotherapy needed a mean of 3.1 ± 1.3 treatment sessions to achieve complete regression of the OL lesions, compared to 6.3 sessions by cotton-swab cryotherapy. OL lesions smaller than 2 cm², located outside the tongue, with epithelial dysplasia, or with a surface keratin layer <55 μm required significantly fewer cryotherapy sessions to achieve a complete regression. Reported recurrence rates were 8-34%, and continued tobacco use was the most consistent risk factor for recurrence. Malignant transformation was observed in 6.6% of OL patients in a long-term cohort. We conclude that cryotherapy is a simple, safe, and effective treatment for OL. Cryogun cryotherapy is more efficient than cotton-swab cryotherapy.