ONCC's Oncology Certified Nurse

Cancer prevention is organized into three levels. Primary prevention eliminates or reduces exposure to risk factors before disease develops (tobacco cessation, vaccination, sun protection, chemoprevention). Secondary prevention detects cancer or precancerous lesions early, when treatment is most effective, chiefly through screening. Tertiary prevention limits complications, disability and recurrence in people who already have cancer (rehabilitation, survivorship surveillance, late-effect management).

Tobacco cessation is the single greatest cancer-prevention opportunity; smoking causes roughly 30% of all U.S. cancer deaths and is linked to cancers of the lung, oral cavity, larynx, esophagus, bladder, kidney, pancreas, stomach, cervix and to acute myeloid leukemia. Benefits of quitting occur at any age, including after a cancer diagnosis, so every tobacco user should be offered cessation support at every visit (Ask, Advise, Refer or the 5 A's), combining counseling with pharmacotherapy (nicotine replacement, varenicline, bupropion).

Diet and weight: high intake of vegetables, fruits, whole grains and fiber and limited red and processed meat reduce colorectal and other cancer risk. Excess body weight increases the risk of postmenopausal breast, colorectal, endometrial, kidney, pancreatic, liver, gallbladder, ovarian and thyroid cancer, multiple myeloma and esophageal adenocarcinoma. Alcohol is a known carcinogen for breast, oral cavity, pharynx, larynx, esophagus, liver and colorectum; the American Cancer Society (ACS) advises that it is best not to drink, and those who do should limit intake to no more than one drink per day for women and two for men.

Physical activity independently lowers risk for colon, breast, endometrial and other cancers through improved insulin regulation, reduced inflammation, lower circulating estrogen and weight control. Adults should aim for 150–300 minutes of moderate or 75–150 minutes of vigorous activity weekly (reaching or exceeding the upper limit is optimal) and limit sedentary time.

Sun protection prevents basal cell, squamous cell and melanoma skin cancers: seek shade, especially 10 a.m. to 4 p.m.; wear protective clothing, a wide-brimmed hat and UV-blocking sunglasses; apply broad-spectrum sunscreen SPF 30 or higher and reapply every 2 hours and after swimming. Indoor tanning significantly increases melanoma risk, particularly when started at a young age.

Infection-related cancers are highly preventable. HPV vaccination prevents cervical, anal, oropharyngeal, vaginal, vulvar and penile cancers. It is routinely given at ages 11–12 (may start at 9); catch-up is recommended through age 26, with shared decision-making for ages 27–45. A 2-dose series is used when started before the 15th birthday; 3 doses are needed when started at 15 or older or in immunocompromised persons. Vaccination does not replace cervical screening. Hepatitis B vaccination prevents hepatocellular carcinoma, and H. pylori eradication removes a risk factor for gastric adenocarcinoma and gastric MALT lymphoma.

Chemoprevention uses medications to reduce cancer risk in high-risk people. The USPSTF recommends offering risk-reducing medication to women at increased breast cancer risk and low risk of adverse effects. Aspirin is no longer recommended to be started solely for colorectal cancer prevention in the general population because bleeding risk offsets the benefit.