Table 2.

Sensitivity, specificity, positive and negative predictive values of p53 immunohistochemistry (IHC) and assessment of dysplasia in the prognosis of potentially malignant oral lesions

Marker	Sensitivity	Specificity	Positive predictive value (PPV)	Negative predictive value (NPV)
Moderate or severe dysplasia*	12/18 (67%)	13/18 (72%)	12/17 (71%)	13/19 (68%)
Suprabasal p53 immunoexpression*	6/18 (33%)	15/18 (83%)	6/9 (67%)	15/27 (56%)
Moderate or severe dysplasia†	10/16 (62.5%)	13/15 (87%)	11/13 (85%)	13/19 (68%)
Suprabasal p53 immunoexpression†	5/17 (29%)	15/15 (100%)	5/5 (100%)	15/27 (56%)

*All lesions entered for analysis, irrespective of presence of the marker at margins of the histological section; †lesions harbouring the marker were only entered for analysis when this extended at least into one margin of the histological section.

Sensitivity: proportion of the “progressive lesions” (cases) that harbour the marker. Specificity: proportion of the “non-progressive lesions” (controls) that do not harbour the marker. PPV: proportion of the lesions harbouring the marker that progressed to carcinoma. NPV: proportion of the lesions not harbouring the marker that did not progress to carcinoma.