Overdiagnosis

Overdiagnosis is the diagnosis of disease that will never cause symptoms or death during a patient's ordinarily expected lifetime[1] and thus presents no practical threat regardless of being pathologic.

Although screening saves lives in some cases, in others it may turn people into patients unnecessarily and may lead to treatments that do no good and perhaps do harm.

Given the tremendous variability that is normal in biology, it is inherent that the more one screens, the more incidental findings will generally be found.

[citation needed] Overdiagnosis is only certain when an individual remains untreated, never develops symptoms of the disease and dies of something else.

A persistent excess of detected disease in the tested group years after the trial is completed constitutes the best evidence that overdiagnosis has occurred.

In advanced age, such as 65 years or older, the concept of overdiagnosis takes on increasing importance as life expectancy decreases.

There are various cancer types for which a standard contraindication to screening is life expectancy of less than 10 years, for the simple and logical reason that a person who already has medically complex health status (e.g., multiple comorbidities) and realistically can probably expect to live for less than 10 years is less likely to get a net benefit (balance of benefit versus harms) from diagnosing and treating that cancer, especially if it may be indolent anyway.

[3][4][5] Some cancers outgrow their blood supply (and are starved), others are recognized by the host's immune system (and are successfully contained), and some are not that aggressive in the first place.

[11] In a letter to the editor, authors not associated with the original study of the data from the randomized clinical trial argued that one-quarter of mammographically detected breast cancers represent overdiagnosis.

[12] A systematic review of mammography screening programs reported an overdiagnosis rate of around 50%, which is the same of saying that a third of diagnosed cases of breast cancer are overdiagnosed.

There is considerable evidence that the problem of overdiagnosis is much greater for lung cancer screening using spiral CT scans.

[citation needed] Issues with overdiagnosis of infectious diseases, such as malaria or typhoid fever, persist in many regions around the world.

[27] Overdiagnosis is often confused with the term "false positive" test results and with misdiagnosis, but they are three distinct concepts.

[29] For instance, a patient that receives a lumbar spine x-ray when they have low back pain without any sinister signs or symptoms (weight loss, fever, lower limb paresthesia, etc.)

[33] It has been proposed that some conditions that are indolent (i.e., unlikely to cause appreciable harm during the patient's lifetime) should have the words "cancer" or "carcinoma" removed from their accepted/preferred medical name.