Abstract
Overdiagnosis refers to the detection of cancers that pose no threat to life and would never have been detected in the absence of screening. It is now a major public health concern throughout the world because advancements in screening technology have substantially increased the detection rates of non-lethal cancers. Cancer overdiagnosis leads to unnecessary treatments, putting patients unnecessarily at risk for the potential morbidity and mortality that may arise from those treatments, and it wastes healthcare resources. Patients may also suffer unnecessary anxiety, job discrimination, financial hardships, and other detrimental effects on quality-of-life following cancer overdiagnosis. In this article, I provide examples of cancer overdiagnosis as a consequence of screening for thyroid, breast, and pancreatic cancers. To mitigate the adverse effects of cancer overdiagnosis, we should adopt only those screening strategies that have been shown in randomized trials to reduce cancer mortality, and we should inform patients about the potential benefits and risks of cancer screening, particularly the risk for overdiagnosis.