Risk Factors: Age
How does age affect the risk of breast cancer?
The biggest risk factor for breast cancer is simply age. Approximately 80% of breast cancers occur in women over age 50, and most cases of breast cancer occur among women in their sixties and seventies. As you get older, your risk of developing breast cancer increases.
Why does aging affect the risk of cancer?
Cancers develop when too many specific genes in a cell are damaged. These are generally genes that control cell division and tissue growth. Some of these genes are called oncogenes, or cancer genes. Genes are constantly damaged as a normal part of living and aging, and may be damaged further by external factors such as poor health habits (smoking, chronic infections) and environmental influences. Fortunately, the damage is also constantly repaired. However, because repair is not perfect, the longer we live, the more damage accumulates.
There are other protective mechanisms that detect damaged cells and send them into programmed cell death, preventing the damaged cells from spawning cancers. Unfortunately, the genes regulating these events may themselves become damaged with age and cease to function properly. When enough genes that regulate cell division and tissue growth are damaged, one cell may no longer respond at all to the signals that would normally keep it from dividing. This cell and its offspring cells will then continue to divide without restraint, causing a cancer.
Sometimes the body's immune surveillance will recognize an early-stage cancer and eradicate it. Other times, it will not. The older you are, the less vigilant your body is about catching early-stage cancers, and the more likely you are to have genetic damage. Cancer is largely a game of chance: the longer you live, the greater your odds of getting cancer.
