Old Age and Cancer
Life is a linear path and aging is an inevitable process. The concern is not only aging but the age related problems especially health problems. One of the deadly diseases which attack the human kind irrespective of age is Cancer. However, statistics reveals that the cases reported are more when people are in higher age group. The biggest question is “why aging brings a huge increase in cancer risk?”
The advancement in medical sciences has elevated the average life expectancy to much higher level around the world. Despite this, the fact can not be ignored that most of the aged elderly are on the threat of being cancer contracted and suffer in later part of their life with pain and agony. The researchers are well aware of the fact and have established the clear evidence of cancer with old age. But they are yet to find out the reason behind it. As said, “Science is an ongoing process and we bear the fruit of toil and the hard work.” We look for the future to guide us in finding out the solution of this problem, along with many more others.
Let us look at some of the thoughts behind the ongoing search of the solution. Daniel Gottschling, a researcher at the Fred Hutchinson Cancer Research Center and professor of genome sciences at the University of Washington fund that “Yeast don't get cancer, but aging yeast cells do get something a lot like it. They too have one of these hallmarks of cancer, they get chromosomal instability, and chromosomes get all mixed up near the end of their life."
Gottschling and his colleague Michael McMurray measured the age of a yeast cell by counting its offspring, called daughter cells, which appeared white. They genetically manipulated the yeast cells to change colour from white to red if there were abnormal chromosomes, a sign of genetic instability. They saw a lot more red when the yeast hit middle age, suggesting there's an age-linked switch for cancer. Studying this switch in yeast could help scientists solve the link between aging and cancer.
Cancer can strike anyone; however, cancer is primarily considered a disease of aging. In the United States as per statistics, in 1900, the average lifespan was 48 years and 3.7% of total deaths were caused by cancer. By 1997, the average lifespan increased to over 76 years, with 23.3% of total deaths caused by cancer. Fifty percent of all malignancies and sixty seven percent of cancer deaths occur in persons over the age of sixty-five. “Between first 30 to 40 years of life you have less chances of getting cancer whereas once you attain the age of fifty, risk and incidence of cancer increases astronomically,” says Gottschling.”
There have been a lot of hypotheses to try to explain the phenomenon of why do humans get cancer as they get older. Unfortunately, because there are so many hypotheses out there, and because we live so long, it's been difficult to figure out which of the hypotheses is actually true.
One hypothesis is that cancer, caused by the accumulation of mutations that ultimately produce a cell capable of uncontrolled growth. The older people are more vulnerable to cancer because they've been exposed to carcinogensâ€” pollution, tobacco, sun, radiation, alcohol, bad diet, and maybe even stressâ€” longer.
The counter arguments are; “It is tempting to think that cancer occurs later in life because of a steady accumulation of mutations," says David Sinclair, pathology professor at Harvard, wrote in an accompanying commentary to Gottschling's research, which was published in Science. He further added, "Certainly, cells isolated from the elderly have more chromosomal abnormalities than cells from the young. But the story is not so simple because rates of spontaneous mutation are too low to account for the extensive genome rearrangements found in tumors."
One more hypothesis suggests that genetic mutations that can lead to cancer tend to occur more frequently in older people. "Experiments in mice have confirmed the suspicion that mutation rates increase with age. The molecular basis of this increase in mutation rate is still under debate," wrote Sinclair.
The DNA repair system in a healthy body is constantly on the lookout for dangerous changes that may cause a cell to become cancerous, and aborts the cell when it finds such mutations. This system is not as effective when people get older. This could be because "genes required for preventing or repairing DNA damage gets mutated, leading to runaway DNA instability," wrote Sinclair.
The encouraging evidence what noted is that with the discovery that is made, where we see this basically equivalent of a cancer-like phenomenon in yeast cells, this now gives some focus into which of those hypotheses might actually be true, and even more so, it gives the potential to test the hypotheses and eventually either drugs or modes of treatment if what is being seen in yeast is true in humans as well.
This research was published in the September 26, 2003 issue of Science and was funded by the National Science Foundation (NSF), the National Institutes of Health (NIH) and Ellison Medical Foundation and provides some hope in the future to combat cancer in elderly people. However, when the real result comes for the end user is to wait and watch as to when the science arm us with real solution of the problem.