The pathway to clinical use of a cancer biomarker.

Biomarkers play a key role in the diagnosis and management of patients with cancer, and are important for fulfilling the promise of precision medicine in oncology. However, although numerous biomarkers have been shown to have clinical validity, many have not undergone rigorous testing to demonstrate clinical utility so that they can be appropriately incorporated into clinical care. This review article highlights the characteristics of a good biomarker and the steps required to demonstrate clinical utility, and gives examples of both successful established biomarkers and promising new tissue-based and circulating biomarkers on the horizon.