As we age, we experience a progressive decline in many of our bodily functions. This decline can vary greatly from individual to individual. One 75 year old might still be very active and participate in strenuous physical activities, while another might require considerable assistance just to perform simple everyday tasks. Aging is variable. It is a highly individualized process that is influenced by a number of genetic, developmental, and environmental factors.
Many things, not simply chronological age, contribute to treatment tolerance and outcome in older patients with cancer, and these present challenges when determining appropriate treatment. Recently, though, members of the EORTC Cancer in the Elderly Task Force, in a paper published in the Journal of Geriatric Oncology, evaluated the physiological reserves of elderly patients with cancer and described the most relevant biomarkers that might potentially serve to indicate their functional biological age.
Dr. Hans Wildiers of the University Hospitals Leuven, Chair of the Cancer in the Elderly Task Force, and co-author of this study, says, "The incidence of most malignant diseases increases with age. Studies have shown that slightly more than half of all newly diagnosed cancer cases and more than two thirds of cancer-related deaths occur in patients 65 years or older. So, we expect the number of older patients with cancer will increase as the population ages. Doctors will increasingly need to make treatment decisions for older patients, and to make effective decisions, we will need better biological markers of aging."
The EORTC Cancer in the Elderly Task Force study provides a guideline on integrating several potential biomarkers of aging: inflammatory markers, telomere length and telomerase activity, genetic predisposition for longevity, gene expression of aging related genes in peripheral blood mononuclear cell, immunosenescence, lymphocyte senescence p16INK4a expression in T lymphocytes, and plasma microRNA expression profile.
They point out that comprehensive geriatric assessment can provide information on the general health status of individuals, but that it is far from perfect as a prognostic or predictive tool for individual patients. Alternatively, biological changes in certain tissues which are the result of adaptive alterations due to past exposures as well as the natural aging process can help to assess aging.