The biology of aging: the current research agenda.

There has been and will continue to be a dramatic shift in the composition of our population with regard to age. Over the next several decades, the percentage of the population that is older than 65 years will nearly double. This has obvious and striking implications, particularly for health care. In anticipation of this change, there has been increased research activity in an attempt to understand the basic biology of aging and the mechanisms whereby older individuals become susceptible to disease. The authors reviewed MEDLINE data from the past 2 decades and key articles from the literature to develop a comprehensive overview of the background and current status of research in biomedical gerontology. They found that research in the mechanisms of aging has expanded strikingly during the past 20 years, and that there is now a more precise understanding of age-associated changes in cellular and molecular functions. Scientific overlap of these age-associated changes with the biology of cancer is now recognized. An appraisal of our current understanding of aging (or lack thereof) is made in this article. Selected key research questions are also presented, some of which are particularly germane to cancer biology and clinical oncology.