The Role of Biomarkers in Guiding Clinical Decision-Making in Oncology

Recent advances in molecular diagnostics have led to the characterization of an increasing number of actionable genomic alterations and immune-based signatures, which have facilitated the development of many highly effective cancer therapies. In addition to their prognostic value, some of these biomarkers have been shown to have predictive value and have had a significant impact on clinical decision-making. The presence of these therapeutic targets can thus aid health-care professionals to select the optimal therapies and avoid use of ineffective, potentially toxic ones. Earlier agents were generally approved for only one or a limited number of malignancies and/or stages, but more recent approvals encompass multiple tumor types that bear a common molecular alteration regardless of tumor type (i.e., tumor-agnostic indications). The expanding use of tumor-agnostic biomarkers has the potential to greatly broaden the use of these therapies to a wider patient population. Yet the rapidly increasing number of tumor-specific and tumor-agnostic biomarkers, and the continually changing treatment guidelines regarding the use of targeted agents and associated testing requirements, present challenges for advanced practitioners to remain current on these topics and their ability to apply these advances to clinical care. Here, we review predictive oncology biomarkers currently in use and their role in clinical decision-making, including those specified in product prescribing information and clinical practice guidelines. Current clinical guidelines regarding recommended targeted therapies for selected malignancies, and when molecular testing should be performed, are discussed.