What is cancer?
Cancer is a term that describes more than 100 types of diseases. It is characterized by an uncontrolled division of cells that can invade different tissues. Cancer is the second leading cause of death in the U.S. and worldwide. It can start anywhere in the human body, but the most common cancer types are lung, colorectal, pancreas, female breast, prostate, and liver cancers.
Mechanism of cancer
Cancer development is a complex process that happens over many years. Cells in our body continuously grow and multiply, replacing old and damaged cells. This process is strictly controlled by various mechanisms. Still, there is a tiny chance of ‘mistakes’ that our body makes from time to time. Usually, the body can detect and fix occurring problems. However, if abnormal cells were not noticed, they can accumulate in the tissue and lead to cancer development.
Those ‘mistakes’ are changes in cell genetic material that is responsible for cell function. It can happen because of errors in cell division or if changes were inherited from parents. Damage of DNA is also a significant factor that can cause cancer development. Agents that can damage DNA and cause cancer are called carcinogens. Some of the most common carcinogens are tobacco, alcohol, ultraviolet rays, engine exhaust, and pollution.
Aging and cancer
There are various risk factors and prevalence data for different cancer types. However, advancing age is considered the most important factor for cancer overall and many individual types of cancer. According to the National Cancer Institute, the median age of a cancer diagnosis is 66 years. That is, half of the cancer cases occur in people below the age of 66 and a half in people above this age.
The effect of carcinogens is cumulative. The more body is exposed to them, the higher level of damage and the more the risk of developing cancer. Also, a larger number of cell divisions means a higher chance of ‘technical mistake’ in DNA. It explains why older people are more likely to have it. In addition, some biological mechanisms that regulate aging also may be involved in developing age-related diseases like cancer.
All changes caused by the mechanisms mentioned above accumulate in the body over many years. But we can reduce damaging factors and significantly decrease the risk of cancer development. Thus, aging is a natural process that does not necessarily lead to cancer. And besides, adults with the most extended longevity are less likely to develop cancer.