Immunzytochemie (p16INK4a) als Zusatzuntersuchung bei zytologischen Befunden der Gruppe III D

Abstract

Pap smears classified as III D (munich classification II) describes cytological abnormalities according to low and/or moderate squamous epithelial dysplasia (CIN 1 and/or CIN 2). This cytological diagnosis-group is in routine procedure marked by an uncertain predictive statement: the positive predictive value is low, but relatively often occurs a higher degree dysplasia (CIN 3) in follow up examinations. Therefore un-certainties arise both for gynecologists and their patients with a view to the ensuring control- and therapy management respectively. In order to clarify the question, whether an additional immunocytochemical examination using p16 (INK4a) can improve the prognostic statement for patients with cytological diagnosis of group III D, the cytological diagnosis, the HPV test results and the results of the CINtec (TM) p16 (INK4a)-Immunocytochemistry in 357 patients were being drawn up parallel or documented. In the case of 115 patients with actual cytological diagnosis group III D a validation could be performed after histological (56) and cytological (59) follow up respectively. In 63.5 % of these III D-patients p16 was graded immunocytochemically positive, in 73.9 % high risk HPV (HC II) was positive. In relation to the entire follow up cytological diagnosis, high risk HPV und p16 detection have a positive predictive value of 53, 65.5 and 82.4 % at the time of evaluation. The negative predictive values are 80.6 % for high risk HPV and 100 % for p16 respectively. In spite of some methodical restrictions and an uncertain predictive statement concerning the graduation of CIN during the histological clarification in the follow up, the use of p16 (INK4a)-Immunocytochemistry can distinctly improve the prognostic statement in routine procedure for patients with cytological diagnosis of group III D.