Absolute risk

Absolute risk refers to the actual numeric chance or probability of developing cancer during a specified time period — for example, within the year, within the next five years, by age 50, by age 70, or during the course of a lifetime.

One type of absolute risk is lifetime risk, which is the probability that an individual will develop cancer during the course of a lifetime. For instance, an American man's absolute risk of developing prostate cancer in his lifetime is about 16 percent. Put another way, about 16 out of every 100 men will develop prostate cancer at some time in their lives. This also means that 84 out of every 100 men won't develop prostate cancer.

Lifetime risk isn't the risk that a person will develop cancer in the next year or the next five years. An individual's cancer risk has a lot to do with other factors, such as age. For instance, a woman's lifetime risk of developing colon and rectal cancer is just under 5 percent, or about 478 out of every 10,000 women. But her risk of developing colon and rectal cancer before the age of 40 is 0.08 percent, or about eight out of every 10,000 women.