What is prevention?

Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will reduce the burden of cancer and lower the number of deaths caused by cancer.

Cancer is not a single disease but a group of related diseases. Our genes, lifestyle, and the environment around us work together to increase or decrease our risk of getting cancer. Each person’s cancer risk is made up of a combination of these factors.

To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.

Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk, but it does not mean that you will not get cancer.

Different ways to prevent cancer are being studied, including:

Changing lifestyle or eating habits

Avoiding things known to cause cancer

Taking medicines to treat a precancerous conditions or to keep cancer from starting

Having risk-reducing surgery.

Breast cancer prevention

Avoiding risk factors and increasing protective factors may help prevent cancer. 

The following are risk factors for breast cancer:

Older age

A personal history of breast cancer or benign (noncancer) breast disease

Inherited risk of breast cancer

Dense breast tissue

Reproductive history resulting in greater exposure to estrogen

Taking hormone therapy for symptoms of menopause

Radiation therapy to the breast or chest

Obesity

Drinking alcohol

The following are protective factors for breast cancer:

Reproductive history resulting in less exposure to estrogen

Taking selective estrogen receptor modulators or aromatase inhibitors and inactivators

Selective estrogen receptor modulators

Aromatase inhibitors and inactivators

Risk-reducing or prophylactic mastectomy

Ovarian ablation

Getting enough exercise

It is not clear whether the following affect the risk of breast cancer:

Hormonal contraceptives

Chemicals in the environment

Studies have shown that some factors have little or no effect on the risk of breast cancer.

Cancer prevention clinical trials are used to study ways to prevent cancer.

New ways to prevent breast cancer are being studied in clinical trials.

Avoiding risk factors and increasing protective factors may help prevent cancer.

Avoiding cancer risk factors may help prevent certain cancers. Risk factors include smoking, having overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.

For more information on breast cancer risk, call 800/4-CANCER.