1. Faculty of Medicine, University of Cologne, 50931 Cologne, Germany
2. Department of Obstetrics and Gynecology, University of Cologne, 50931 Cologne, Germany
3. Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf, Germany
4. Department of Obstetrics and Gynecology, Hospital of the City of Cologne, 51069 Cologne, Germany
5. Department of Pathology, University of Cologne, 50931 Cologne, Germany