Innovations in Prevention and Screening include studies on early detection that can save lives through diagnosis and treatment. Cancer screening research however, paints a more complex picture that has raised questions about screening effectiveness, benefits versus risks, and implementation. There is a consensus among cancer researchers that a decrease in cancer-specific mortality rates is the best indicator of screening’s effectiveness. Analyses of randomized controlled trials comparing mortality rates of screened populations for breast, cervical, and colorectal cancers with non-screened populations indicate that screening is effective. For example, women ages 50 to 70 in the United Kingdom offered regular breast cancer screening had an estimated 20-percent reduction in deaths from breast cancer compared with women not offered screening.