Das Bethesda-System - eine Verbesserung der Klassifikation der Zervixzytologie?

Abstract

Cervical cytology screening programmes have significantly reduced cervical cancer mortality. In 1988 the National Cancer Institute developed a new classification for reporting cervical cytology--"The Bethesda System". The aim of our study was to compare the clinical usefulness of this new classification with the classification used in German-speaking countries (which discriminates cytologically between moderate and severe dysplasia) including a verbal classification predicting the histological grade of cervical intraepithelial neoplasia (CIN I, II, III). 671 patients with abnormal cervical cytology results and subsequent conisation or hysterectomy were included. We correlated cytological and histological diagnosis (gold standard). In cases of cytologically suggested moderate dysplasia we found histologically CIN I, CIN II and CIN III in 11%, 41% and 42%, respectively. Our results show that discrimination of CIN II and CIN III by means of cytology is limited. Using our therapy schedules we found that adequate therapy is possible by each of the cytological classification systems. The cervical smear is used as a screening test to determine which women require further examination using colposcopy. Under these circumstances an adequate therapy is possible with both classifications. The results underline the importance of colposcopy in the management of cervical dysplasia. As long as conisation is commonly used in German-speaking countries as the only diagnostic tool after an abnormal cervical smear the Bethesda System increases the risk of overtreatment.