Table 1.

Biomarkers of Biological Age for Potential Use in Oncology Settings

Measures	Process of Aging Measured	Sensitive to change?	Predicts outcomes?	Practicality	Citations
Biomarkers
p16INK4	Cellular senescence	Yes	Unknown	New approaches in development	65,73,29,30
Epigenetic clocks	DNA methylation/damage	Yes	Yes	High cost; common lab protocols	4,31,32
Telomere length	Cell specific aging	Yes	Yes; inconsistent findings	Low cost; strict technical protocols needed	27,37–39
IL-6, CRP, TNFRII	Inflammation	Yes	Yes	Low cost; common protocols	8,40
Clinical Indices 1
Pace of aging	Physiological system dysfunction 2	Yes	Yes	Can be derived from medical record	4,41
Deficit accumulation indices	Loss of function 2	Yes	Yes	Easy to estimate with patient-reported data and medical record	6
Frailty indices	Global measure2	Yes	Yes	Requires personnel to administer	44,74
Geriatric assessments	Global measure 2	unknown	Yes	Requires personnel to administer; takes about 15–20 minutes	6,23,27,42–44,74,75
Sarcopenia	Muscle atrophy	Yes	Yes	Requires CAT scan	43
Allostatic load	Physiological System Dysfunction	Yes	Yes	Can be derived from medical record	27,33,50,51

^1.Clinical indices use combinations of measures included on Table 1.

^2.Global measures capture some combination of chronic diseases (comorbidity), organ system function and physiological reserve (e.g., glycated hemoglobin, forced expiratory volume in one second (FEV1), systolic blood pressure, total cholesterol, creatinine, blood urea nitrogen, hematocrit, etc.), function domains such as physical function (e.g., get up and go, grip strength, gait speed, walk stairs, etc.), cognitive function, and ability to perform activities of daily living.