What is the definition of the specificity of a screening test?

The specificity of a screening test is defined as its ability to correctly identify those without the disease, in this case, individuals who do not have cancer. This measure is crucial because it indicates the test's capacity to minimize false positive results, allowing healthcare providers to avoid unnecessary anxiety and further invasive testing for those who are cancer-free. High specificity means that most of the healthy individuals will be correctly identified as such, which is vital for effective screening protocols.

Other elements mentioned in the options, such as the ability to identify those with cancer, cost-effectiveness, and frequency of conduct, do not pertain to the definition of specificity. Instead, they relate to different aspects of screening tests, such as sensitivity, economic considerations, or the logistics of implementing screening programs.