Podoplanin expression in oral leukoplakia: prognostic value and clinicopathological implications

Oral Diseases (2012) 18 , 692–699 Objectives: Current clinicopathological parameters cannot predict the risk of malignant transformation in oral leukoplakia sufficiently. Recent studies have shown that podoplanin is expressed in oral cancer and precancerous lesions. The aim of our study was to assess whether podoplanin expression in pretreatment biopsies could serve as a biomarker to predict the risk of malignant transformation in patients with oral leukoplakia. Materials and Methods: In this retrospective study, podoplanin expression was analysed in 60 patients with previously untreated oral leukoplakia by immunohistochemistry. We investigated the associations between podoplanin expression and various clinicopathological variables including oral cancer‐free survival (OCFS) and the SIN‐classification. Results: The chi‐square‐test revealed that high expression of podoplanin in pretreatment biopsies was associated with malignant transformation (P = 0.003) and increasing SIN‐classification (P = 0.009). In univariate analysis, podoplanin expression in oral leukoplakia had a significant impact on OCFS (P = 0.009). The 5‐year OCFS rate decreased from 100% for patients with no podoplanin expression to 41.7% for patients with the highest level of podoplanin expression. Conclusion: Although podoplanin expression and the SIN‐classification served as factors to predict malignant transformation in patients with oral leukoplakia in univariate analysis, no significant impact was found for both factors in multivariate analysis.