Principles of Cancer Screening

In 1968, Wilson and Jungner (WJ) put together the following criteria of screening approved by the World Health Organization (WHO) [1]. 1. The condition sought should be an important health problem. 2. There should be an accepted treatment for patients with recognized disease. 3. Facilities for diagnosis and treatment should be available. 4. There should be a recognizable latent or early symptomatic stage. 5. There should be a suitable test or examination. 6. The test should be acceptable to the population. 7. The natural history of the condition, including development from latent to declared disease, should be adequately understood. 8. There should be an agreed policy on whom to treat as patients. 9. The cost of case-finding (including diagnosis and treatment of patients diagnosed) should be economically balanced in relation to possible expenditure on medical care as a whole. 10. Case-finding should be a continuing process and not a "once and for all" project. Recently, the WHO officers have updated the WJ criteria taking into account recent developments in genetic and genomic medicine, among many other factors. Synthesis of emerging screening criteria proposed over the past 40 years 1. The screening program should respond to a recognized need. 2. The objectives of screening should be defined at the outset. 3. There should be a defined target population. 4. There should be scientific evidence of screening program effectiveness. 5. The program should integrate education, testing, clinical services and program management. 6. There should be quality assurance, with mechanisms to minimize potential risks of screening. 7. The program should ensure informed choice, confidentiality and respect for autonomy. 8. The program should promote equity and access to screening for the entire target population. 9. Program evaluation should be planned from the outset. 10. The overall benefits of screening should outweigh the harm. The perfect example of successful screening is cervical cancer (CC), a “fairytale” of gynecological oncology. • The HPV virus is a known cause of cervical dysplasia and cancer. CC, therefore, is a sexually transmitted disease. • CC has known precursors – various degrees of cervical dysplasia.