Understanding Your Cancer Risk—and What You Can Do About It

Cancer touches many of our lives—the American Cancer Society estimates about 1.9 million new cancer cases are diagnosed per year. While we can’t fully predict whether any individual will develop a form of cancer, some people are at an increased risk.

Cancer risk factors are anything that increases the chance that a person will develop cancer. Having an increased risk does not mean you will develop cancer, just as having no known risk factors does not guarantee that you will not develop cancer. But knowing your individual level of risk can help you make informed, proactive decisions about your long-term health.

Understanding Your Chance of Developing Cancer

Physicians and cancer researchers describe cancer risk using two different risk factor calculations. Absolute risk describes the average person’s chance of developing a certain type of cancer. Relative risk compares the chance a person in a certain group will develop cancer to the risk of others in another group.

For example, the average risk of a woman in the United States developing breast cancer is one in eight. But for some groups of women, like those with dense breasts or those with a genetic mutation in the BRCA genes, cancer incidence rates are higher. This means that women with those risk factors have a higher chance of developing breast cancer than woman who do not.

Your cancer risk level does not tell you whether you will or will not develop cancer. Someone with an average risk of developing breast cancer may be diagnosed while someone with a BRCA gene mutation never develops cancer. But your risk level can determine whether you need certain types of screening or, in some cases, a change in lifestyle or environmental choices.

What Cancer Risk Factors Can I Control?

Some lifestyle and environmental factors have been linked to an increase of risk in certain cancers. In these cases, you may be able to reduce your risk of developing cancer by making a change in your lifestyle. Common risk factors you may be able to modify include:

• Smoking and tobacco use: Tobacco use is linked to several types of cancer, including lung cancer. Quitting smoking can reduce your risk level.
• Infections like HPV or hepatitis B: HPV is linked to an increased risk of several cancers, including cervical cancer, while hepatitis B can increase your risk of developing liver cancer. Both viruses have FDA approved vaccines. Getting vaccinated as recommended can prevent infection and help you avoid an increased cancer risk.
• Skin damage from sun exposure: Ultraviolet radiation from sunlight is the main cause of nonmelanoma skin cancers. Taking precautions while exposed to the sun, like wearing sunscreen, can reduce your risk of developing these cancers.
• Exposure to some toxic chemicals: Links have been found between indoor and outdoor air pollution and some forms of cancer. Reducing your exposure to secondhand smoke, asbestos, and outdoor pollution may help lower your risk of developing cancer.
• Diet: Diets that are heavy in red meat, processed meat, sugar-sweetened beverages, or highly processed foods can negatively affect your health. Eating well by incorporating vegetables, foods high in vitamins, fiber, fruit, and whole grains may help reduce your cancer risk.
• Alcohol use: Alcohol is linked to increased risk of several types of cancer. If you do choose to drink alcohol, you should limit your intake to no more than two drinks per day for men and one drink per day for women.
• Physical activity: Regular physical activity can lower your risk of developing cancer. For most adults, 150-300 minutes of moderate activity or 75-150 minutes of vigorous activity is recommended.
• Obesity: Being overweight or obese can increase the risk of several cancers. Your physician can help you determine a healthy weight for you and the best way to maintain it.

Talk to your physician about what changes you can make to maintain a healthy lifestyle and reduce your risk level.

Common Risk Factors You Cannot Control

While some risk factors can be reduced by lifestyle changes, there are other risk factors that cannot be avoided:

• For many cancers, risk can increase with age.
• A family history of cancer may indicate a genetic mutation linked to certain forms of cancer.
• Some races and ethnicities have a higher incidence rate of certain cancers.

While you cannot change any of these risk factors, knowing your personal risk level can guide the decisions you make with your physician for your health. Your physician may recommend you start cancer screening at an earlier age or at more frequent intervals than the routine recommendation. Your physician may also recommend additional screening above and beyond what is usually recommended. For example, dense breast tissue, which may be linked to a higher risk of breast cancer, can make it harder to see cancer on a mammogram. A physician may recommend a woman with this risk factor be screened with a three-dimensional mammogram, ultrasound, or MRI.

If you have a higher risk of developing cancer due to a factor you cannot control or avoid, please talk to your physician about the precautions you can take to prevent cancer or detect cancer early.

What to Ask Your Doctor About Cancer Prevention

It’s important to have the information you need to make informed decisions about your health. Your healthcare team can help you navigate any questions you may have. You may want to ask:

• What risk factors for cancer do I have, and what do they mean for my chance of developing cancer?
• Are there any behaviors I can change to reduce or eliminate my risk of developing cancer?
• What screening tests do you recommend?
• How does my family health history affect my risk of developing cancer?
• Would you recommend genetic testing based on my family’s health history?

Regardless of your risk level for developing cancer, talk to your doctor about recommended screening guidelines.  Screening is an important part of detecting cancer in an early stage, when it is often easier to treat. Screening may also detect precancerous conditions in cervical and colorectal cancers, which can be treated before they develop into cancer.

If you have any concerns about your health or risk level, please contact your physician.