What are cancer markers?
cancer markers are simply defined as substances that are produced on abnormal levels in the bodies of people with cancer. These markers are usually proteins and can be detected in body fluids such as blood or urine or in a sample of biopsy tissue. Cancer tumor markers may apply to substances that are directly responsible for tumor growth or metastasis, or may refer to substances produced by the body in response to cancer. It was assumed that the discovery of cancer markers would lead to simple blood or urine tests that could be used as diagnostic tools for various cancer. Scientists and doctors have been very excited about this prospect because the ability to detect cancer in the early stages can dramatically improve the outcome. Unfortunately, it failed, as it originally hoped. Many of the proposed Cancer tumor markers are produced at low levels in people who do not have associated cancer because many other conditions than cancerIt can lead to the production of most of these markers. In addition, not all people with specific cancer will produce cancer markers. This is most often in the early stages of cancer. Since most of these markers lack specificity, they are rarely used as a diagnostic tool.
Despite these disadvantages, several cancer markers are considered possible screening tools. Probably the most famous of these is antigen specific to the prostate (dog), which can be used to screen prostate cancer in men. Although many men with high levels of dog often show that it does not have prostate cancer, the test detects cancer in many men in early stages that would not otherwise be unnoticed.
The CA-125 brand is sometimes used as a toolscreening Women for ovarian cancer. However, this marker is considered less sensitive than a dog and has a relatively high level of false positIV and false negatives. The main problem with this marker is that excessive production of the CA-125 may be the result of gynecological problems that have nothing to do with ovarian cancer.
cancer markers are best used in individuals to monitor cancer treatment or to predict recurrence or relapse of cancer. This is because this method measures cancer marker for the same person for a period of time. In these cases, a sudden decline or sudden promotion of a specific marker is likely to be a favorable response to treatment or risk of cancer relapse.