Incorporating biomarkers of frailty and senescence in cancer therapeutic trials.

As the population ages, oncologists are faced with the quandary of how to efficiently identify frail individuals that may have more difficulty tolerating and recovering from systemic therapy for cancer. Recent advances have been made in recognizing frailty via clinical geriatric assessment of older patients with cancer. These advances appear to allow for better prediction of toxicity than physician-rated performance status. Although the development of these tools is a large step forward in geriatric oncology, we still lack an understanding of how the underlying biologic processes of aging affect tolerance of cancer treatment. Determining specific biologic causes underlying frailty may allow oncologists to become even more adept at identifying patients at risk for excessive toxicity and provide the opportunity to therapeutically target these processes to help improve tolerability and survival outcomes for older patients with cancer. This article provides a background on potential biologic factors that may identify frail individuals at increased risk for toxicity related to cancer treatment. Potential methods to incorporate these factors into cancer therapeutic trials are discussed.