Cancer mortality rates continue to decrease in the United States; part of this decrease results from reductions in tobacco use since cigarette smoking is the most important preventable cause of cancer. Primary prevention of skin cancer consists of restricting exposure to ultraviolet light by wearing appropriate clothing and use of sunscreens. In the past two decades, there has been a three-fold incidence of squamous cell carcinoma and a fourfold increase in melanoma in the United States. Persons who engage in regular physical exercise and avoid obesity have lower rates of breast and colon cancer.
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 stage, when treatment works best. CDC offers free or low-cost mammograms and Pap tests nationwide, and free or low-cost colorectal cancer screening in six states.
Vaccines (shots) also help lower cancer risk. The human papillomavirus (HPV) vaccine helps prevent most cervical cancers and several other kinds of cancer, and the hepatitis B vaccine can help lower liver cancer risk.
A person’s cancer risk can be reduced with healthy choices like avoiding tobacco, limiting alcohol use, protecting your skin from the sun and avoiding indoor tanning, eating a diet rich in fruits and vegetables, keeping a healthy weight, and being physically active.
It’s a rough guide at best. The vast majority of such symptoms are caused by nonmalignant disorders, and cancers can produce symptoms that don’t show up on the list, such as unexplained weight loss or fatigue. But it is a useful reminder to listen to your body and report sounds of distress to your doctor.
It sounds too good to be true, but it’s not. Scientists at the Harvard School of Public Health estimate that up to 75% of American cancer deaths can be prevented; the table below summarizes their research on the causes of cancer in the United States. The American Cancer Society is only slightly less optimistic about prevention, estimating that about 60% of America’s cancer deaths can be avoided. And a 2005 study argues that over 2.4 million of the world’s 7 million annual cancer deaths can be blamed on nine potentially correctable risk factors.
Screening and Early Detection
Screening prevents death from cancers of the breast, colon, and cervix. Current cancer screening recommendations from the USPSTE.
A greater understanding of the underlying biology of many cancers, as well as technological advances in areas such as imaging, are creating new avenues for advances in screening and early detection.
In addition, population-based studies have identified groups of people often part of specific racial, ethnic, or socioeconomic groups who are more likely to be diagnosed with certain cancers. As a result, researchers are now studying ways to improve the use of and access to proven screening methods in these population groups.
Importantly, studies performed over the last decade have strongly suggested that, in addition to benefits, screening has downsides. In particular, there is the risk of overdiagnosis and overtreatment the diagnosis and treatment of cancers that would not threaten life or cause symptoms.
Overdiagnosis and overtreatment expose patients unnecessarily to the potential physical harms of unneeded and often invasive diagnostic tests and treatment, as well as to the psychological stresses associated with a cancer diagnosis. This understanding has led to intensive study of ways to identify and distinguish those screen-detected cancers that are truly life threatening and require immediate treatment from those for which treatment is unnecessary or can be safely delayed.
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