Cancer Risk Factors

Many factors can increase your risk of developing cancer. They include changes in your genes called mutations. Lifestyle choices — what you eat and drink, exercise, smoking and other choices — can also raise your risk of developing cancer.

Gene Mutations

Gene mutations can be inherited — passed from parents to children. Also called germline mutations, inherited mutations are rare, accounting for only 10% of cancers.

Other gene mutations can develop any time during your life. They are called somatic and happen when a change in the DNA of cells leads to the formation of cancer. Somatic mutations are not inherited.

You can’t control gene mutations, but if you know you may have a gene mutation that increases your risk of developing cancer, work with your health care team to access genetic testing and counseling. If you have an inherited gene mutation, the experts in our Hereditary Cancer Risk Clinic can evaluate your risk factors and create a plan to reduce your cancer risk.

Lifestyle Choices

Lifestyle choices also present cancer risks. You can control many of them. Thirty to 50% of all cancers may be prevented with lifestyle changes. Discuss your risks with your doctor to come up with a risk reduction plan.

Tobacco Use

• Smoking: Causes about 30% of all cancer deaths; linked to lung, throat, mouth, bladder, kidney, liver, stomach, pancreas, colorectal and cervical cancers
• Smokeless tobacco: Increases risk for oral, esophageal and pancreatic cancers
• Secondhand smoke: Raises lung cancer risk by 20% to 30% in non-smokers

Diet and Nutrition

• Processed and smoked meats (bacon, sausage, hot dogs): Linked to colorectal cancer
• Red meat (excessive consumption): Associated with colorectal and possibly, other gastrointestinal cancers
• Not eating enough fruits and vegetables: Reduces protective effects against multiple cancers due to loss of important micronutrients and fiber fruits and vegetables supply
• High-sugar diets:
  • May increase cancer risk indirectly through obesity.
  • Not connected to weight gain: Preclinical research has linked consuming too much sugar in food and beverages to developing several cancers because high sucrose or high fructose diets can activate pathways (such as inflammation, glucose and lipid metabolic pathways) that lead to cancer (pmc.ncbi.nlm.nih.gov/articles/PMC9775518/).
• Drinking alcohol: Raises risk of mouth, throat, esophagus, liver, larynx (voice box), colorectal and breast cancers. A 2025 U.S. Department of Health and Human Services advisory determined that there are no safe levels of alcohol consumption for men and women, challenging the belief that moderate drinking is safe or could have health benefits.

Physical Activity and Weight

• Obesity: Linked to at least 13 types of cancer including endometrial, breast (post-menopausal), colorectal, kidney, pancreatic and liver cancers
• Sedentary lifestyle: Independent risk factor for several cancers

Other Lifestyle Factors

• Sun exposure: UV radiation from the sun is the primary cause of skin cancers (melanoma and non-melanoma)
• Using indoor tanning beds: Increases melanoma risk by 75% when tanning beds are used before age 35
• Chronic stress: May influence cancer progression through immune suppression
• Poor sleep: Disrupted circadian rhythms are linked to increased cancer risk
• Reproductive factors: Delayed childbearing and not breastfeeding can increase breast cancer risk

Infections

• HPV (human papilloma virus): Causes cervical, anal, penile, vaginal, vulvar and oropharyngeal cancers
• Hepatitis B and C: Major risk factors for liver cancer
• H. pylori: Associated with stomach cancer and certain lymphomas

Environmental Exposure

• Air pollution: Associated with lung cancer risk
• Radon exposure: Second leading cause of lung cancer in the U.S.

Preventing Cancer, Reducing Cancer Risks

Work with your health care team to evaluate your cancer risk factors and develop a plan to change or manage factors that are under your control.

• As recommended by your doctor:
  • Get age- and risk factor- appropriate cancer screenings for breast, cervical, colon, lung and prostate cancers.
  • Get vaccinated against cancer-causing infections (HPV, Hepatitis B).
• Modify lifestyle choices when you can, including:
  • Stop using tobacco; get help from your doctor, clinician or a smoking cessation program.
  • Reduce your alcohol intake — and consider eliminating alcohol completely if you are at high risk for cancer.
  • Eat a diet rich in fruits, vegetables whole grains; avoid processed foods.
  • Maintain a healthy weight for your age and height.
  • Get regular physical activity (150+ minutes/week); it can reduce risk of breast, colorectal and other cancers by 10 to 30%.
  • Use sun protection with an SPF of at least 30 — this applies to people with light and darker skin tones. Both can develop skin cancer. Don’t use tanning beds.