What Is Cancer? Cancer is a term used for diseases in which abnormal cells divide without control and are able to invade other tissues. Cancer cells can spread to other parts of the body through the blood and lymph systems. Cancer is not just one disease, but many diseases. There are more than 100 different types of cancer.
How Can Cancer Be Prevented? The number of new cancer cases can be reduced, and many cancer deaths can be prevented. Research shows that screening for cervical and colorectal cancers as recommended helps prevent these diseases by finding precancerous lesions so they can be treated before they become cancerous.
Screening for cervical, colorectal, and breast cancers also helps find these diseases at an early, often highly treatable stage. Vaccines also help reduce cancer risk. The human papillomavirus (HPV) vaccine helps prevent most cervical cancers and some vaginal and vulvar cancers, and the hepatitis B vaccine can help reduce liver cancer risk.
A person's cancer risk can be reduced in other ways by receiving regular medical care, avoiding tobacco, limiting alcohol use, avoiding excessive exposure to ultraviolet rays from the sun and tanning beds, eating a diet rich in fruits and vegetables, maintaining a healthy weight, and being physically active.
Other Ways to Reduce Cancer Risk You can reduce your risk of getting cancer in a variety of ways, including keeping a healthy weight, avoiding tobacco, limiting the amount of alcohol you drink, and protecting your skin from the sun.
Keeping a Healthy Weight Research has shown that being overweight or obese substantially raises a person's risk of getting endometrial (uterine), breast, prostate, and colorectal cancers. Overweight is defined as a body mass index (BMI) of 25 to 29, and obesity is defined as a BMI of 30 or higher.
Avoiding Tobacco Lung cancer is the leading cause of cancer death, and cigarette smoking causes almost all cases. Compared to nonsmokers, men who smoke are about 23 times more likely to develop lung cancer and women who smoke are about 13 times more likely. Smoking causes about 90% of lung cancer deaths in men and almost 80% in women. Smoking also causes cancer of the voicebox (larynx), mouth and throat, esophagus, bladder, kidney, pancreas, cervix, and stomach, and causes acute myeloid leukemia.
Second-hand Smoke Adults who are exposed to second-hand smoke at home or at work increase their risk of developing lung cancer by 20% to 30%. Concentrations of many cancer-causing and toxic chemicals are higher in secondhand smoke than in the smoke inhaled by smokers.
Limiting Alcohol Intake Studies around the world have shown that drinking alcohol regularly increases the risk of getting mouth, voice box, and throat cancers. A large number of studies provide strong evidence that drinking alcohol is a risk factor for primary liver cancer, and more than 100 studies have found an increased risk of breast cancer with increasing alcohol intake. The link between alcohol consumption and colorectal (colon) cancer has been reported in more than 50 studies.
Protecting Your Skin from the Sun Skin cancer is the most common form of cancer in the United States. Exposure to the sun's ultraviolet (UV) rays appears to be the most important environmental factor involved with developing skin cancer. To help prevent skin cancer while still having fun outdoors, protect yourself by seeking shade, applying sunscreen, and wearing sun-protective clothing, a hat, and sunglasses.