Fig. 5

Macrophage infiltration as predictive marker for malignant transformation of OLP. Analyses for CD68 epithelial (Fig. 5a), CD68 subepithelial (Fig. 5b) and CD163 epithelial (Fig. 5c) are given. ROC curves for macrophage infiltration based on the positive cells/mm² are presented (left column). The diagrams are a plot of the sensitivity (true-positive rate) vs. 1-specificity (false-positive rate) over all possible macrophage marker expression values. The circle shows the points of the highest Youden (Y) indices which are associated with the COP (malignant transformation vs. no malignant transformation). The AUC value is indicated. Diagrams in the right column show the division of the test and control group (transforming OLP and non-transforming OLP) into positive and negative subgroups based on the ascertained COPs of macrophage marker expression: a CD68 epithelial, b CD68 subepithelial, c CD163 epithelial. Using the χ² test, the specimens were judged positive (malignant transformation expected) if macrophage marker expression was above the COP and negative (no malignant transformation expected) if macrophage marker expression was below the COP. Increased macrophage marker expression levels in transforming OLP (group 1) compared to non-transforming OLP (group 2) were significant. AUC area under the curve, COP cut-off point, OLP oral leukoplakia, OSCC oral squamous cell carcinoma, ROC receiver operating characteristic