Leading risk factors for preventable cancers are smoking, getting too much UV radiation from the sun or tanning beds, being overweight or having obesity, and drinking too much alcohol. Some kinds of cancer (like breast, cervical, and colorectal) can be caught early through screening. Other kinds can be prevented—for example, cervical cancer through vaccination and colorectal cancer through removal of abnormal growths in the colon and rectum before they turn into cancer.

Symptoms

Smoking and secondhand smoke cause about 90% of lung cancer deaths in the United States. Smoking also causes cancer of the voice box (larynx), mouth and throat, esophagus, urinary bladder, kidney, pancreas, cervix, colon, rectum, liver, and stomach, as well as a type of blood cancer called acute myeloid leukemia. About 34 million US adults smoke cigarettes, and every day, about 1,600 young people under age 18 try their first cigarette.
Nonsmokers who are exposed to secondhand smoke at home or at work have a 20% to 30% higher risk of lung cancer. Secondhand smoke causes more than 7,300 lung cancer deaths among US nonsmokers each year. In the United States, 58 million nonsmokers are exposed to secondhand smoke every year.

Skin cancer is the most common cancer in the United States. Most cases of melanoma, the deadliest kind of skin cancer, are caused by exposure to ultraviolet (UV) light from the sun or tanning beds. Although use of sun protection has increased slightly in recent years, sunburn is common in the United States, with about one-third of adults and over half of high school students getting sunburned each year.

Excessive alcohol use, either in the form of binge drinking (5 or more drinks on an occasion for men or 4 or more drinks on an occasion for women) or heavy drinking (15 or more drinks per week for men or 8 or more drinks per week for women), increases the risk of cancer of the breast (in women), liver, colon, rectum, mouth, pharynx, larynx, and esophagus. About 17% of US adults report binge drinking, and 6% report heavy drinking.

Treatment

Screening tests and further treatments can help prevent colorectal and cervical cancers.