Risk Reduction of Cervical Cancer Through HPV Screening and Vaccination—Assumptions and Reality

Cancer is a leading cause of death worldwide. It is estimated that about 20 % of all cancer deaths are originally caused by infectious diseases, making them an important risk factor. The classical approach to lower cancer risk has been the screening for precancerous lesions. In addition, screening for primary infections has become an option in order to evaluate individual cancer risks and to offer an intensive follow-up and intervention for patients who have tested positive. Furthermore, vaccines have been developed to prevent high risk infections and subsequent malignant diseases in the first place. Prospective epidemiological studies are necessary to evaluate the effect of prevention methods on cancer incidences but will give results only after a very long follow-up period. Therefore, mathematical models for risk prediction and risk reduction will be helpful tools to determine the effectiveness of screening and prevention programs. In this chapter we discuss cervical cancer as an example of a malignancy which may in many cases be preventable. During the last decades cervical cancer screening was based on cytological abnormalities. Since human papillomaviruses (HPV) have been identified to be the main risk factor for cervical cancer, the detection of HPV DNA in cells of the cervix has been investigated as a surrogate marker for high cancer risk. Here, we give an overview about the epidemiology and natural course of cervical cancer and HPV infections. We discuss benefits and limitations of current screening and prevention options which include cytology, histology, HPV detection, and HPV vaccination. Finally, we make special emphasis on the complex factors that need to be considered when developing mathematical models for prediction of risk reduction of cancer rates.