Cancer screening

Cancer screening aims to detect cancer before symptoms appear. This may involve blood tests, urine tests, DNA tests other tests, or medical imaging. The benefits of screening in terms of cancer prevention, early detection and subsequent treatment must be weighed against any harms. Cancer screening aims to detect cancer before symptoms appear. This may involve blood tests, urine tests, DNA tests other tests, or medical imaging. The benefits of screening in terms of cancer prevention, early detection and subsequent treatment must be weighed against any harms. Universal screening, also known as mass screening or population screening, involves screening everyone, usually within a specific age group. Selective screening identifies people who are known to be at higher risk of developing cancer, such as people with a family history of cancer. Screening can lead to false positive results and subsequent invasive procedures. Screening can also lead to false negative results, where an existing cancer is missed. Controversy arises when it is not clear if the benefits of screening outweigh the risks of the screening procedure itself, and any follow-up diagnostic tests and treatments. Screening tests must be effective, safe, well-tolerated with acceptably low rates of false positive and false negative results. If signs of cancer are detected, more definitive and invasive follow-up tests are performed to reach a diagnosis. Screening for cancer can lead to cancer prevention and earlier diagnosis. Early diagnosis may lead to higher rates of successful treatment and extended life. However, it may also falsely appear to increase the time to death through lead time bias or length time bias. The goal of cancer screening is to provide useful health information which can guide medical treatment. A good cancer screening is one which would detect when a person has cancer so that the person could seek treatment to protect their health. Good cancer screening would not be more likely to cause harm than to provide useful information. In general, cancer screening has risks and should not be done except with a medical indication. Different kinds of cancer screening procedures have different risks, but good tests share some characteristics. If a test detects cancer, then that test result should also lead to options for treatment. Good tests come with a patient explanation of why that person has high enough risk of cancer to justify the test. Part of the testing experience is for the health care provider to explain how common false positive results are so that the patient can understand the context of their results. If multiple tests are available, then any test should be presented along with other options. Screening for cancer is controversial in cases when it is not yet known if the test actually saves lives. Screening can lead to substantial false positive result and subsequent invasive procedures. The controversy arises when it is not clear if the benefits of screening outweigh the risks of follow-up diagnostic tests and cancer treatments. Cancer screening is not indicated unless life expectancy is greater than five years and the benefit is uncertain over the age of 70. Several factors are considered to determine whether the benefits of screening outweigh the risks and the costs of screening. These factors include: Breast cancer screening is the medical screening of asymptomatic, apparently healthy women for breast cancer in an attempt to achieve an earlier diagnosis. The assumption is that early detection will improve outcomes. A number of screening tests have been employed, including clinical and self breast exams, mammography, genetic screening, ultrasound, and magnetic resonance imaging. The use of mammography in universal screening for breast cancer is controversial as it may not reduce all-cause mortality and for causing harms through unnecessary treatments and medical procedures. Many national organizations recommend it for most older women.