Malignant transformation of oral epithelial dysplasia: a real-world evaluation of histopathologic grading.

OBJECTIVE: This study describes the predictive value of oral epithelial dysplasia (OED) grading as an indicator for malignant transformation and progression. STUDY DESIGN: The records of an Australian-based pathology laboratory were searched for oral mucosal biopsies with a dysplastic or malignant diagnosis. Examination for an association with progression and malignant transformation without reinterpretation was performed. Analysis was undertaken using hazard ratios and the Fisher exact test. RESULTS: A total of 368 patients with a diagnosis of OED were included. Twenty-six patients (7.1%) underwent progression or malignant transformation; the annual malignant transformation rate was 1%. No other characteristics were associated with a heightened risk of progression or transformation. CONCLUSIONS: The severity of OED was not associated with risk of malignant transformation, suggesting that the current OED grading system is not useful for predicting patient outcomes or for determining management strategies. Definitive treatment of all OED is recommended, until a more reliable progression/transformation system is developed.