The Challenging Landscape of Cancer and Aging: Charting a Way Forward
Thanks to improvements in health care, life expectancy in
both the United States and globally is substantially longer now than it was 50
years ago.
In 2010, more than 40 million people in the United
States, or 13% of the population, were older than age 65. This demographic, the
fastest-growing segment of the population, will more than double to nearly 84
million, or more than 20% of the population, by 2050.
The convergence of an overall aging population and a peak
cancer incidence among those aged 65 to 74 will result in a significant rise in
the number of people diagnosed with cancer. Cancer also occurs at a high rate
in people older than 75, but at that age people are more likely to die from
other medical conditions.)
Age is a well-recognized risk factor for cancer
development. In fact, you could say aging is the major carcinogen. The
normal aging process affects many important biological processes within our
bodies that result in the deterioration of proteins and DNA in cells. Many of
these damaged cells enter a state of arrested growth, called “senescence”—no
longer dividing and growing, but still remaining metabolically active and
capable of causing problems. Senescence is an efficient protective mechanism
against cancer, forcing would-be cancer cells to stop dividing. But the
senescence mechanism sometimes fails, and accumulating cancer-causing mutations
produce the uncontrollable cell growth that—with a supportive microenvironment—causes
the formation and spread of cancer.
The longer we live, the more errors our genes accumulate. Over time,
these mutations can lead to cancer. Indeed, there is much still to learn about why
this situation occurs in elderly patients and to look up for a treatm
