Screening for cancer should be done in the following circumstances: When distinct high-risk groups can be identified such as people who have a family history of breast, ovarian, pancreatic, hematologic, colonic, or prostate cancers When a screening test is proved to have a benefit that exceeds risk and is recommended by competent health authorities Recommended screening schedules are constantly evolving based on ongoing studies (see table Screening Procedures in Average-Risk Asymptomatic People as Recommended by the American Cancer Society (ACS), US Preventive Services Task Force (USPSTF), and American College of Physicians (ACP)).