Cancer Screening

Cancer screening tests aim to find cancer before it causes symptoms and when it may be easier to treat successfully. An effective screening test is one that

• Finds cancer early
• Reduces the chance that someone who is screened regularly will die from the cancer
• Has more potential benefits than harms (possible harms of screening tests include bleeding or other physical damage, false-positive or false-negative test results, and overdiagnosis—the diagnosis of cancers that would not have caused problems and did not need treatment)