What Are The Different Types Of Tumor Markers And Why Are They Done?
A tumor marker is a substance that is produced in response to cancer in the body. It is made by both cancer cells and healthy cells. It is found in the blood, urine, tissue or body fluids of a person who has cancer. Tumor markers are also known as biomarkers and cancer markers. It can be antigen, protein or hormones.
A tumor marker test measures tumor markers in blood, urine or tissue. Tumor markers are not specific, and the level of tumor markers in the body will be high for non-cancer medical conditions as well. Other tests are also performed along with a tumor marker test to detect cancers.
Why Are Tumor Marker Tests Used?
This test helps diagnose cancer in a person, that helps the doctor in determining the treatment for cancer. Sometimes, tumor marker tests are used even before a person has symptoms of cancer, especially if that person has a high risk of cancer.
Most people have tumor markers at low levels in their body. But if a person has cancer, the level of these tumor markers can increase a lot. If the results indicate a high tumor marker level, it may indicate cancer. But these tests are commonly used to-
- Determine the type of treatment for cancer.
- Check whether the treatment is working or not.
- Find out whether a person has cancer or not.
- Predict the chance of recovery of a person.
- Check for cancer recurrence, after the treatment.
- Check if cancer has spread or not.
- Check for cancer in a person with a strong family history of a certain type of cancer.
Types of Tumor Markers
Prostate-specific Antigen(PSA)
This type of tumor marker is normally present in low amounts in males. High level of PSA is a symptom for prostate cancer. Elevated levels also indicate Benign Prostatic Hyperplasia(BPH) and prostatitis. By checking the levels of PSA, a doctor can analyze the response of a patient after treatment. For the tumor marker test, your blood sample will be analysed. Determining PSA levels are helpful to diagnose prostate cancer, screening for prostate cancer, check for cancer recurrence and to monitor treatment.
Alpha-fetoprotein(AFP)
AFP is produced by the developing fetus in higher amounts. The level of AFP will be very high in pregnant women. Normally AFP is not found in males and non-pregnant women. If it is present, it indicates-
- Ovarian Cancer
- Liver Cancer
- Testicular cancer
A rise of AFP levels can also be due to Non-cancerous medical conditions. For the tumor marker test, your blood sample will be analysed. AFP levels are used to evaluate cancer treatment, predict a chance for recovery, to determine the stage of cancer, and in the diagnosis of liver cancer.
Prostatic Acid Phosphatase(PAP)
Prostatic Acid Phosphatase is a tumor marker produced by the prostate gland. In the blood, Prostatic Acid Phosphatase is present in small amounts. High level of Prostatic Acid Phosphatase indicates medical conditions such as-
- Testicular cancer
- Prostate cancer
- Non-Hodgkin’s lymphoma
- Leukaemia
A rise of PAP levels can also be due to Non-cancerous medical conditions. For this tumor marker test, your blood sample will be analysed.
Carcinoembryonic Antigen(CEA)
It is a protein normally found in adults, in small amounts. High level of Carcinoembryonic Antigen indicates-
- Colorectal cancer
- Stomach cancer
- Lung Cancer
- Ovarian cancer
- Breast cancer
- Thyroid Cancer
A CEA test helps in the diagnosis of some cancers and check if the treatment is working or not. For the tumor marker test, your blood sample will be analysed. CEA levels are used to evaluate cancer treatment and check if there is a recurrence of cancer.
Cancer Antigen 125 (CA 125)
CA 125 blood test measures Cancer Antigen 125 in the blood. An elevated CA 125 level indicates-
- Lung Cancer
- Pancreatic cancer
- Colon cancer
- Uterine cancer
- Breast cancer
- Liver cancer
- Digestive tract cancer
A rise of CA 125 levels can also be due to non-cancerous medical conditions. For the tumor marker test, your blood sample will be analysed. The CA 125 level is used to determine whether a treatment for cancer is working or not and if there is cancer recurrence even after treatment.
CA 19-9
High-level of CA 19-9 indicates
- Bile duct cancer
- Stomach cancer
- Colon cancer
- Pancreatic cancer
- Pancreatitis
- Cholecystitis
- Gallstones
- Liver cirrhosis
For the tumor marker test, your blood sample will be analysed.
Human Chorionic Gonadotropin(HCG)
HCG is a hormone normally present in pregnant women, that is produced by the placenta. If HCG is present in males and non-pregnant females, it indicates-
- Lung cancer
- Ovarian cancer
- Pancreatic cancer
- Testicular cancer
- Liver cancer
- Stomach cancer
For the tumor marker test, your blood or urine sample will be analysed.
CA 27-29 and CA 15-3
This marker is used for treatment evaluation of women with advanced breast cancer. An elevated level of CA 27-29 indicates-
- Liver cancer
- Pancreatic cancer
- Lung cancer
- Stomach cancer
- Breast cancer
- Colon Cancer
- Ovarian cancer
- Kidney cancer
- Uterine cancer
- Ovarian cysts
- Benign breast disease
- Liver disease
- Endometriosis
- Kidney disease
For the tumor marker test, your blood sample will be analysed.
Lactate Dehydrogenase(LDH)
It is an enzyme which is normally found in small amounts in the body. But it’s not very beneficial in detecting a specific type of cancer since LDH level can rise because of many cancers. LDH levels are used to monitor cancer treatment, guide cancer treatment, find out the stage of cancer and check for cancer recurrence. Elevated levels of LDH indicate-
- Testicular tumor
- Germ cell tumor
- Hypothyroidism
- Liver diseases
- Lung diseases
- Heart failure
- Anaemia
How are Tumor Marker Tests Done?
Blood test, urine test and biopsy are various ways to check for tumor markers. Among these, a blood test is the most common blood test for cancer detection. In a biopsy, a small piece of tissue is taken for testing.
A blood test normally takes less than 5 minutes. The blood sample will be collected by inserting a needle into your vein. A vial or test tube collects a small amount of blood. In the case of a urine test, the healthcare professional will analyse the urine sample in the laboratory.
For biopsy, either by scraping or cutting the skin, a small piece of tissue will be taken. A special needle is used to obtain the tissue from inside of your body.
Prior to the blood or urine test, you don’t need any special preparation. Sometimes, you have to fast before biopsy.
What do the Results Indicate?
There are two false chances for a tumor marker test. If it is a false positive, it indicates that a person has cancer, even if the person has no cancer. A false negative indicates that a person has no cancer, even if the person has cancer. Therefore along with tumor marker tests, other diagnostic tests are also done.
The results can help to
- Know if the treatment is working or not
- Diagnose the stage of cancer
- Plan the treatment
- Check whether there is cancer recurrence after treatment
- Detect the type of cancer
The information provided by tumor marker might be limited since-
- Tumor markers are limited to some types of cancers.
- Tumor markers are absent in some people who have cancer
- Some Non-malignant conditions cause an elevated tumor marker level
The levels of tumor markers vary over time. Therefore you have to repeat the tests. Tumor marker tests are considered as the primary diagnostic method, for detailed analysis, scans and other minor procedures are carried out.