There is an epidemic in the United States of cancer over-diagnosis. Medical experts agree that this epidemic is a result of aggressive screening programs.
These aggressive screening programs referred to include mammograms finding tiny cancers, and PSA tests discovering unpalpable prostate cancers.
Over-diagnosis is not the same thing as a misdiagnosis. If a pathologist looks under a microscope and classifies a group of benign calls as being cancerous, that is a misdiagnosis.
Over-diagnosis is also not the same thing as a false positive test result. A false-positive is when a mammogram reveals a suspicious shadow or when a PSA test is elevated, doctors follow up with additional tests which usually results in a biopsy of the suspected lesion.
Over-diagnosis occurs when screening detects a tumor that would not have presented clinically in the absence of screening. For example, is a mammogram revels a tiny breast cancer in a 103- year old woman, a cancer that if left alone would not grow large enough to cause symptoms for another decade, that mammogram would probably have over-diagnosed her cancer.
Obviously physicians do not typically screen 103-year-old women for breast cancer. However, the extremeness of this hypothetical case demonstrates a factor that strongly influences the rate of over-diagnosis.
The science of estimating cancer over-diagnosis is complex. Researchers are working to standardize the way researcher conduct their studies
Until there is a uniformed manner of investigation it is important to keep in mind that cancer over-diagnosis is a real phenomenon, which urges the public to be cautious about adopting aggressive cancer screening strategies.