Library · Method
Screening
Make it clearer
Screening means testing people who have no symptoms to look for a disease before it becomes noticeable. The idea is to find it early, when it is easier to treat.
With cancer, a screening test usually doesn't provide the diagnosis; it works as a first filter. A mammogram, for example, can find a lump in the breast, and that lump could be cancer or something else; more tests are needed to know.
And most cancer screening tests carry risks. A smoke alarm can go off because of toast or stay silent during a fire, and screening works in a similar way. A false positive is a result that shows cancer where there is none, and it often leads to more tests. A false negative is the opposite: the result looks normal even though cancer is there.
In brief
Screening means testing people for disease before symptoms appear; it can find the disease early, when it is easier to treat.
In cancer, screening usually doesn't diagnose: a lump on a mammogram can be cancer or something else, and more tests are needed.
Most cancer screening tests have risks: a false positive shows cancer that isn't there and often leads to more tests; a false negative looks normal even when cancer is present.
A smoke alarm can go off with no fire or stay silent during one.
Sources (2)
- MedlinePlus, U.S. National Library of MedicineHealth Screening, MedlinePlusPublished
- National Cancer Institute, National Institutes of HealthCancer Screening Overview (PDQ), Patient VersionPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated