Screening tests and their appropriate use should be carefully evaluated before launching screening programs as a matter of public policy.

Screening examinations, tests, or procedures are usually not diagnostic of cancer. Rather it indicate that cancer may be present. The diagnosis is then made following a work up that include  a biopsy and histopathologic confirmation.

A number of genes have been identified that predispose a person to the disease. Many more will be identified. Testing for these genes can define a high risk individuals or population. The ability to predict the development of a particular cancer may some day present therapeutic options as well as ethical dilemmas. It may eventually allow for an early intervention to prevent a cancer or limit its severity. Currently, persons at high risk can engage in intensive screening.

Widespread screening for breast, cervix, colon, and prostate cancer is beneficial for certain age groups. The details of the individual screening tests and procedures for these cancers will not be discussed in this article.