Screening to detect cancer in individuals showing no signs
or symptoms of the disease they are being screened for can
have tremendous bene;ts (see sidebar on Cancer Screening).
However, it can also cause unintended harm, and this
has made it di;cult to develop strategies for screening
for the majority of cancer types. For a screening program
to be successful, it must meet two important criteria: It
must decrease deaths from the screened cancer, and the
bene;ts it provides must outweigh any harms. Determining
whether a screening program meets these criteria requires
an enormous amount of research and careful analysis of the
In the United States, an independent group of experts
convened by the Public Health Service rigorously evaluates
clinical research to make evidence-based recommendations
about clinical preventive services, including cancer-
screening tests. ;ese experts form the U.S. Preventive
Services Task Force (USPSTF). As of Aug. 1, 2014, the
USPSTF recommended that certain segments of the general
population be screened for just four types of cancer (see
sidebar on USPSTF Cancer-screening Recommendations, p.
29). In addition to considering evidence regarding potential
new screening programs, the USPSTF routinely evaluates
new research regarding established screening programs, and
can revise recommendations if deemed necessary.