What is meant by a "complete response" in cancer treatment?

In the context of cancer treatment, a "complete response" refers to the complete disappearance of all evidence of cancer following therapeutic intervention. This means that imaging studies, physical examinations, and any relevant laboratory tests show no signs of active disease. Achieving a complete response is an important goal in oncology, as it indicates that the cancer has responded positively to treatment and has been eradicated from the patient's body.

This definition underscores the importance of rigorous monitoring and evaluation in cancer care, as the distinction between a complete response and other responses—such as significant reductions in tumor size or stable disease—can influence treatment decisions and prognostic assessments. Thus, a complete response is the most definitive outcome indicating the absence of detectable cancer.