When the immune system is weakened, does the risk of cancer increase?

This article was written by doctors of Internal Oncology Department, Vinmec Times City International General Hospital.

The immune system is essential for life. Without an immune system, the body will be easily attacked by bacteria, viruses, parasites, etc.. the immune system keeps us healthy when exposed to pathogens. The immune system is located throughout the body and involves many types of cells, organs, proteins, and tissues. It is important that the immune system be able to distinguish the body's own tissue from foreign tissue. Dead or damaged cells are also recognized and eliminated by the immune system. The immune system also plays an important role in cancer risk. This statement has been drawn from recent studies.

Every year more than 8 million people die from cancer globally. Essentially, cancer is caused by a series of genetic mutations that accumulate over time. Certain factors such as smoking, alcohol consumption and obesity can also increase the rate at which these gene mutations occur and thus increase the risk of cancer. However, not all risk factors can be avoided; eg age. As age increases, the risk of cancer also increases. So why does aging significantly increase cancer risk? A research team recently provided an unexpected answer to this question.

As you age, the likelihood of mutations increases. The older you get, the more mutations you have and the greater your risk of cancer.
In a recent study - conducted at the University of Dundee in the UK, the team hypothesized to demonstrate that the risk of cancer increases with age due to an aging immune system. The immune system becomes less effective as we age, making us more susceptible to disease.
Figure 2 depicts the research results of the Japan Institute of Biological Therapy

The thymus, one of the important organs of the immune system, is where T cells - cells that play a key role in the immune system are formed and developed. Much of the decline in the immune system over time is due to a decline in the thymus gland.
The thymus begins to shrink from the age of 1. The thymus halves in size every 16 years, and so does the production of T cells.
Researchers took data from 2 million cancers in people aged 18 and designed a mathematical model that predicts increased cancer rates associated with a weakened immune system. Here, the researchers found that their model fit the data more closely than the multiple mutation hypothesis.
Dr. Sam Palmer of the University of Dundee explains, "Cancer cells are constantly arising in the body but normally the immune system destroys them before new tumors establish themselves. T cells are persistent. scan for cancer cells."
"When the immune system is weakened, the number of cancer cells has a chance to grow. This risk increases with age as the thymus gland shrinks."
"Imagine a battle between T cells and cancer cells, in the end the cancer cells win if they grow beyond a certain threshold."
"This threshold will decrease with age, proportional to the amount of T cells produced," Dr. Palmer added. "This simple hypothesis turns out to be able to explain many of the problems with cancer incidence."

The risk of age-related cancer is generally higher in men than in women. The cause may be explained by the faster decline of the thymus gland in men than in women, which has not been previously explained by the multiple mutation hypothesis.
Dr Thea Newman, senior researcher, said, "It's still very early, but if proven true, it could offer a whole new way to treat and prevent cancer."
She added, "Previously, nearly all cancer research was based on understanding genetic mutations to cure disease."
"We are not arguing that mutations cause cancer," continued Dr. Newman, "but whether the question of mutations alone can account for the rapid increase in cancer rates, in aging also causes other profound changes in the body."
Thymus expert Professor Clare Blackburn, at the University of Edinburgh, said, "This suggests that in addition to the problems of mutations, we should also focus on how to enhance thymic function, possibly by transplantation. transplant or controlled regeneration, so we can increase the number of T cells produced."
She added, "It is also important to consider the unintended consequences of doing this and how to minimize them."
These findings are fascinating and open a new avenue for researchers to treat cancer.
Autologous immunotherapy is currently being performed at Vinmec Hospital to enhance immune cells both in quantity and quality. This technique, transferred from the Japanese Institute of Biology, is being applied to many patients with very good results. Currently, this technique in Japan is indicated not only for cancer patients undergoing and after treatment, but also approved by the Japanese Ministry of Health to be performed on healthy people who have not yet had cancer. Aim to help reduce the risk of cancer by strengthening the body's immune system

Source: Medical News Today