Cancer Screening and Early Detection

Abstract

Overview Cancer screening is a means of early detection of malignancy in an asymptomatic individual at risk for the disease. A positive screening test calls for additional diagnostic tests. The purpose of screening is to find a small, localized tumor that is destined to grow, metastasize, and kill before it spreads. Effective treatment can then lead to prevention of death. Simply finding disease is not adequate proof of benefit. Proper evaluation of a screening test involves demonstration that it leads to reduced risk of death. Screening is a population‐based intervention; appropriate individuals should be in a program of routine screening. Screening and treatment involve interventions which are often invasive. Proper evaluation of a screening program involves assessment of outcomes and a comparison of the benefits and risks.