Scientists have discovered why older people are more likely to suffer from cancer

© Fotolia / Spectral-Design3D image of a cancer cellScientists have discovered why older people are more likely to suffer from cancer© Fotolia / Spectral-Design

. The weakening of the immune system was one of the main reasons why older people are much more likely to suffer from cancer than children and young people, said in an article published in the journal PNAS.

«Now, while this is still early to say, but if we’re right, then it turns out that the cancer needs to be treated quite well, as it is doing today. Now all efforts are focused on the study of mutations and combat. We are not saying that they do not cause cancer, but wonder whether their accumulation in itself increase the likelihood of occurrence of tumor growth age?»—says the TEM Newman (Newman Thean) from the University of Dundee (Scotland).

Cancer is considered today one of the leading causes of death in developed countries, and its main feature is the fact that the frequency of its development grows significantly in older years. Scientists assume that this is due to two things – the deterioration of the body’s ability to repair breaks in DNA at the onset of old age and the accumulation of the number of potentially dangerous but non-fatal mutations in the genome.

Newman and her colleagues believe that the accumulation of mutations in cells is not the main reason why cancer often affects older people, paying attention to one thing associated with aging of the human body.

Scottish biologists have noticed that in the body of humans and all other mammals there is one on whose work is continuously deteriorating virtually from the moment of birth of its owner – the thymus, a special gland, where born and are taught the main conductors of the immune system called T cells.

T cells play a key role in recognizing various threats to the organism, including viruses, bacteria and cancer cells, and «inciting» other Taurus is immune to them. As a rule, the number of these cells gradually decreases with human aging, including due to the fact that the size of the thymus gradually decreases, and it is overgrown with connective and adipose tissue. For this reason, as biologists now believe, elderly people and animals more susceptible to germs and viruses than their younger counterparts.

This idea prompted the team Newman on the idea that reducing the size of the thymus and the number of T cells may similarly influence the likelihood of developing cancer. To test this idea, scientists have created a mathematical model that describes how the immune cells interact with single cancer cells can turn into tumor.

In this model, cancer cells appeared inside the body with some fixed speed which is not dependent on the age of the individual. The probability of their survival, in turn, depends on how often they encounter immune cells. Using these calculations, the scientists calculated the probability of survival of cancer cells in young and elderly body, and compared these figures with how often cancer occurs in reality.

As it turned out, this idea is much better suited for real data than the predictions obtained using the classic «mutation» model. For example, the idea of Newman and her colleagues might explain why older men are more likely to suffer from cancer than women — their immune system grows old faster, and many other oddities in the development of some rare types of tumors.

All this, according to biologists, suggests that effective cancer control is necessary not only to suppress the development of mutations, but also stimulate the thymus gland and the entire immune system in General. This idea can be to check out how they make Newman and her colleagues transplanted the thymus of a young animal in the body of older individuals, and tracing how this will affect the chances of developing cancer.