Accurate histological grading of cervical intraepithelial neoplasia (CIN) is essential for clinical management. However, CIN grading has a moderate inter- and intra-observer agreement. We investigated the reproducibility and the performance of a score system based solely on the cumulative score value of the biomarkers Ki-67 and p16ink4a (immuno-score).
The immuno-scores were compared to consensus pathologist CIN grading (3 pathologists) based on the combined interpretation of slides stained for H&E, Ki-67 and p16ink4a, and to individual CIN grading
The results show that the cumulative immuno-score (varying from 0-6) of a three tiered score for p16 ink4a and Ki-67 staining has a higher reproducibility than the scores of the individual pathologists for CIN grading (H&E alone or combined with interpretation of immunohistochemistry). In addition, the accuracy of the immuno-score to predict underlying high-grade consensus pathologist CIN grade was at least as good as the individual pathologists CIN grading.
Thus, the selection of an area with abnormal cervical epithelium and subsequent separate assessment of the p16ink4a and Ki-67 immuno-score, results in a more reproducible performance of CIN grading compared to the classical way of grading. In the presentation the scientific background and the consequences of the use of this system for clinical practice will be highlighted