The discovery of an abnormality by health professionals through a special effort designed to screen for asymptomatic disease, or by people themselves who have been made alert to the existence of signs or symptoms
Finding the disease at an early stage, before it has grown large or spread to other sites. Many forms of cancer can reach an advanced stage without causing symptoms. A PSA blood test can help to find early prostate cancer.
Any device, marker, or other means developed for the purpose of detecting the presence of a tumor early in its development, when it is theoretically more likely to be curable. Also education and promotion related to the benefits of early detection.