Predictive value of dysplasia grading and DNA ploidy for malignant transformation of oral potentially malignant disorders
Menée à partir de données portant sur 1 401 patients présentant des lésions suspectes de la cavité buccale, cette étude évalue la sensibilité et la spécificité de deux tests, l'un reposant sur l'analyse du niveau de dysplasie du tissu lésé et l'autre sur l'analyse de la ploïdie cellulaire, pour prédire le risque de transformation maligne des lésions potentiellement cancéreuses
Dysplasia grading is widely used to assess risk of transformation in oral potentially malignant disorders despite limited data on predictive value. DNA ploidy analysis has been proposed as an alternative. This study examines the prognostic value for both tests used in a routine diagnostic setting to inform clinical management. A retrospective study of conventional dysplasia grading was performed on 1401 patients. DNA ploidy analysis was performed on a subset of 273 patients and results correlated with clinical information, pathological diagnosis and outcome over 5-15 years. Malignant transformation occurred in 32 of 273 patients (12%) and, of these, 20 (63%) of pre-existing index lesions were aneuploid. Of 241 patients not developing carcinoma, only 39 (16%) of index lesions were aneuploid. Epithelial dysplasia correlated with DNA ploidy status (p<0•001). The overall positive predictive value for malignant transformation by DNA aneuploidy was 38.5% (sensitivity 65.2% and specificity 75%) and by severe dysplasia grade 39.5% (sensitivity 30% and specificity 98%). DNA diploid and tetraploid status had negative predictive value of 90-96%. Combining DNA ploidy analysis with dysplasia grading gives a higher predictive value than either technique alone. Each of three traditional dysplasia grades predicts a significantly different risk of carcinoma development and time to transformation. DNA ploidy analysis had equivalent predictive value and also detected additional risk lesions in the absence of dysplasia.
Cancer Prevention Research , résumé, 2013