Tumor markers are substances that can be found in the body as a marker of a tumor or cancer. Examination of tumor markers is generally carried out as part of an examination for early detection (screening) of cancer, cancer diagnosis, and determining cancer treatment and the success of cancer therapy.
Tumor markers are a type of substance or antigen produced by cancer cells. This substance can be found in blood, urine, feces, and other body tissues. High levels of tumor markers can indicate the presence of disease, especially cancer.
However, high levels of tumor markers do not absolutely indicate that there is cancer. This is because some normal body cells can also produce tumor markers.
Tumor Marker Examination
Examination of tumor markers is usually carried out in patients who are at risk of cancer, suspected of having cancer, and cancer patients who are currently on cancer treatment.
There are several reasons why examination of tumor markers is important, including:
- Detect the type, size, and stage or stage of cancer.
- Knowing whether cancer cells have spread to other body tissues.
- Determine the right cancer treatment method.
- Predict the success rate of treatment.
- Monitor progress of cancer treatment outcomes.
- Detect cancer that reappears after treatment is complete.
- Early detection of cancer in people who are at high risk of cancer, for example, people who have parents or siblings with a history of cancer.
Examination of tumor markers can be done by three methods, namely urine tests, blood tests, and biopsies. The sample taken will be sent to a pathologist for analysis in the laboratory.
Tumor Markers Commonly Used in Cancer Screening
There are a number of tumor markers that are commonly used in laboratory tests. Some tumor markers are used to detect only one type of cancer and others to detect several types of cancer.
The following are the most common tumor markers used in cancer screening:
1. CEA (carcinoembryonic antigen)
CEA is a tumor marker substance used in the examination of several types of cancer, including colon cancer, lung cancer, stomach cancer, thyroid cancer, pancreatic cancer, breast cancer, bladder cancer, and ovarian cancer.
In addition to detecting cancer, the CEA examination also aims to monitor the progress of treatment results and detect cancer cells that reappear after the patient has finished cancer treatment.
2. AFP (alpha-fetoprotein)
AFP is a tumor marker substance used in screening for liver cancer, ovarian cancer, and testicular cancer. Its use is to diagnose the three types of cancer, determine the stage or stage of cancer, monitor treatment success, and predict cure rates.
3. B2M (Beta 2-microglobulin)
B2M is a tumor marker substance used in the examination of blood cancer, multiple myeloma, and lymphoma. Its use is to monitor treatment success and predict cure rates.
4. PSA (prostate-specific antigen)
PSA is a tumor marker substance that is often used in prostate cancer screening. Its usefulness is to help diagnose prostate cancer, monitor the progress of cancer treatment that the patient is currently undergoing, and detect cancer that reappears after completion of treatment.
However, PSA levels are usually elevated in the presence of benign prostate enlargement (BPH).
5. CA 125 (cancer antigen 125)
CA 125 is a tumor marker used to determine the success rate of treatment for ovarian cancer patients. Examination of tumor markers is also useful for detecting whether ovarian cancer reappears after completion of treatment.
6. CA 15-3 and CA 27-29 (cancer antigens 15-3 and 27-29)
CA 15-3 and CA 27-29 are tumor markers used to monitor treatment outcomes in breast cancer patients.
The use of tumor markers in cancer screening may vary, depending on the condition and medical history, as well as the symptoms experienced by the patient.
When the results of the tumor marker examination show a positive result or there is an increase in the number of tumor markers, it does not mean that you are definitely diagnosed with cancer.
Tumor markers are usually elevated in other diseases, such as hepatitis, kidney disease, pancreatitis, pelvic inflammatory disease, and inflammatory bowel disease. Tumor markers can also be found in pregnant women and people who have a smoking habit.
In addition, not all cancer patients have high levels of tumor markers in their bodies. If the results of the examination show that the tumor marker in the body is low, it does not mean that there is no cancer in the body.
Therefore, to diagnose cancer, it takes a series of examinations consisting of a physical examination, radiological examination, including X-ray, ultrasound, CT scan, and MRI, examination of tumor markers, and biopsy.
To detect cancer early, you are advised to have a health examination or medical check-up regularly to the doctor every few years, especially if you have a risk for cancer. During the examination, the doctor will determine what type of tumor markers need to be examined along with other types of examinations needed.