Biomarkers in oncology: trials and tribulations.

Few apparently promising oncology biomarkers actually make their way into routine clinical use. There are many reasons for this lack of success, and the complexity of cancer biology is only one of the reasons. Challenges involved in evaluating the analytical and the clinical performance of cancer biomarkers account for the lack of successful translation to the clinic. The lack of clear definition of the clinical need often results in tests that may perform reproducibly but are not used because they do not help with important patient care decisions. The National Cancer Institute Cancer Diagnosis Program launched the Program for the Assessment of Clinical Cancer Tests in an effort to move biomarkers more efficiently and effectively into the clinic. A development pathway is proposed that defines the steps required for evaluation of a biomarker assay's analytical and clinical performance. Several pilot projects are ongoing to test the process, and these are described.