Cancer risk refers to a person’s chance of developing cancer. A risk factor is any substance or condition that increases the risk of developing cancer.
There are very few cancers that have a single, known cause. Most cancers seem to be the result of a complex mix of many risk factors. These risk factors may play different roles in starting cancer and helping it grow. Some risk factors include heredity (genetics), lifestyle choices and exposure to cancer-causing substances (carcinogens) in the environment.
Over the years, researchers have developed a better understanding of how cancers develop and grow. Researchers look at all the scientific information to determine whether a substance causes, or could cause, cancer. Scientists carefully review evidence from studies done in people and in the laboratory to determine whether a substance may increase the risk of cancer.
Scientists usually look at 3 things to determine if something is a risk factor for cancer:
People are often concerned about their personal risk of developing cancer. Risk assessment involves looking at information about a person (such as their age, health history, family history, lifestyle and diet choices) to estimate their cancer risk. Knowing your risk factors can help you make personal health choices to reduce your risk of developing certain cancers. Doctors use a variety of risk assessment tools to estimate a person’s risk of developing cancer.
You can avoid some risk factors, such as tobacco. Other risk factors, like age or certain genes, cannot be avoided. Risk reduction (or prevention) means taking action to lower the risk of developing cancer. About half of all cancers can be prevented through healthy living and policies that protect the public.
There are things you can do to lower your overall chance of developing certain types of cancer and stay well. For example, eating a healthy diet that includes a variety of vegetables and fruit each day may reduce the risk of cancer.
Even people who make healthy choices and do everything they can to reduce their risk can develop cancer. Some people develop cancer without having any identifiable risk factors.