Unlike diagnosis efforts prompted by symptoms and medical signs, cancer screening involves efforts to detect cancer after it has formed, but before any noticeable symptoms appear.[117] This may involve physical examination, blood or urine tests, or medical imaging.[117]
Cancer screening is currently not possible for many types of cancers, and even when tests are available, they may not be recommended for everyone. Universal screening or mass screening involves screening everyone.[118] Selective screening identifies people who are known to be at higher risk of developing cancer, such as people with a family history of cancer.[118] Several factors are considered to determine whether the benefits of screening outweigh the risks and the costs of screening.[117] These factors include:
The USPSTF recommends mammography for breast cancer screening every two years for those 50–74 years old; however, they do not recommend either breast self-examination or clinical breast examination.[130] A 2011 Cochrane review came to slightly different conclusions with respect to breast cancer screening stating that routine mammography may do more harm than good.[131]
Japan screens for gastric cancer using photofluorography due to the high incidence there.[6]
Genetic testing for individuals at high-risk of certain cancers is recommended.[132]
Carriers of these mutations may then undergo enhanced surveillance,
chemoprevention, or preventative surgery to reduce their subsequent
risk.[132]
Cancer screening is currently not possible for many types of cancers, and even when tests are available, they may not be recommended for everyone. Universal screening or mass screening involves screening everyone.[118] Selective screening identifies people who are known to be at higher risk of developing cancer, such as people with a family history of cancer.[118] Several factors are considered to determine whether the benefits of screening outweigh the risks and the costs of screening.[117] These factors include:
- Possible harms from the screening test: for example, X-ray images involve exposure to potentially harmful ionizing radiation.
- The likelihood of the test correctly identifying cancer.
- The likelihood of cancer being present: Screening is not normally useful for rare cancers.
- Possible harms from follow-up procedures.
- Whether suitable treatment is available.
- Whether early detection improves treatment outcomes.
- Whether the cancer will ever need treatment.
- Whether the test is acceptable to the people: If a screening test is too burdensome (for example, being extremely painful), then people will refuse to participate.[118]
- Cost of the test.
Recommendations
The U.S. Preventive Services Task Force (USPSTF) strongly recommends cervical cancer screening in women who are sexually active and have a cervix at least until the age of 65.[119] They recommend that Americans be screened for colorectal cancer via fecal occult blood testing, sigmoidoscopy, or colonoscopy starting at age 50 until age 75.[120] There is insufficient evidence to recommend for or against screening for skin cancer,[121] oral cancer,[122] lung cancer,[123] or prostate cancer in men under 75.[124] Routine screening is not recommended for bladder cancer,[125] testicular cancer,[126] ovarian cancer,[127] pancreatic cancer,[128] or prostate cancer.[129]The USPSTF recommends mammography for breast cancer screening every two years for those 50–74 years old; however, they do not recommend either breast self-examination or clinical breast examination.[130] A 2011 Cochrane review came to slightly different conclusions with respect to breast cancer screening stating that routine mammography may do more harm than good.[131]
Japan screens for gastric cancer using photofluorography due to the high incidence there.[6]
Genetic testing
See also: Cancer syndrome
| Gene | Cancer types |
|---|---|
| BRCA1, BRCA2 | Breast, ovarian, pancreatic |
| HNPCC, MLH1, MSH2, MSH6, PMS1, PMS2 | Colon, uterine, small bowel, stomach, urinary tract |
No comments:
Post a Comment