Predictive testing of early CIN behaviour by molecular biomarkers.

Each year, 330,000 new Cervical Intraepithelial Neoplasias(CIN) occur in the European Union (EU) of which 120,000 are early CIN where grade (1, 2) indicates the progression-risk to CIN-3 and therefore determines the treatment choice. However, the Positive Predictive Value (PPV) of CIN grade to predict progression is low (10% and 20% for CIN-1 and -2 respectively, 16% on average) resulting in an enormous number of over-treatments indicating worrisome grade reproducibility.Certain molecular biomarkers such as Ki-67 have a higher PPV (30%, an improvement of 14%), which in Europe alone could improve treatment for many thousands of women per year with considerable cost reduction for the health care system. The quantitative Ki-67 prognostic model has been validated in independent retrospective and prospective studies from different laboratories. Moreover, the PPV of Ki-67 alone can be improved by additional molecular biomarkers (retinoblastoma protein = Rb, cytokeratins= CK-14/-13). Combined Ki67-Rb allows a 2-tiered progression-risk subgroup assignment as very low ( approximately 0% progression, 71% of all CIN-I/II patients)and high risk (48% progression risk, incidence 32%), leaving a small (7% of all) prognostically undetermined group (17% progression). Additional CK-14 and -13 analysis can sub-classify the high-risk in an intermediate and very high risk subgroup(with 40% and 100% progression risks respectively).Thus, molecular biomarkers are potentially important determinators of early CIN lesion behaviour. Important factors for widespread acceptance of molecular biomarkers are (1) market penetration by user-friendly equipment, (2) (inter)national keeping of GLP conditions (reproducibility, independent validation), requiring customer-driven industrial efforts,governmental measures, and additional PPV improvement to further reduce over-treatment.