Risk Factors Associated With Malignant Transformation in Patients With Oral Leukoplakia in a Chinese Population: A Retrospective Study

Abstract

The study aim was to investigate the risk factors for the progression of oral leukoplakia (OLK) to malignancy. The data from 2,628 patients with OLK were retrospectively reviewed. Of these 2,628 patients, 192 had undergone sequential biopsies and were separated into 4 groups according to their final diagnosis. The risk factors were analyzed using Kaplan-Meier univariate survival analysis and Cox multivariate analysis. In 41 of the 2,628 patients (1.7%), the OLK had progressed to cancer, with a mean interval to malignancy of 26.7months. Of the 192 patients with sequential biopsies, OLK was maintained or had progressed to mild, moderate, or severe dysplasia or carcinoma in 50, 66, 35, and 41 patients, respectively. The 3- and 5-year oral cancer-free survival (OCFS) was 78.9 and 72.5%, respectively. The factors associated with worse overall survival were lesions located in the ventral tongue (P=.04), alcohol use (P=.025), nonhomogeneous lesions (P<.01), and high-risk dysplasia (P<.01). Cox regression analyses indicated that nonhomogeneous lesions (P=.03) and high-risk dysplasia (P<.01) were independent prognostic factors for the progression of OLK to malignancy. High-risk dysplasia and nonhomogeneous lesions were shown to be important factors for progression to malignancy in patients with OLK. Thus, such patients should receive close follow-up and undergo sequential biopsies in the first 2 to 3years for early screening of OLK evolving into a malignancy.