What are the other Names for this Test? (Equivalent Terms)
- Biological Tumor Marker Test
- Biomarker Test
What is Tumor Marker Test? (Background Information)
- Tumor markers are substances that supplement other examinations and investigations in diagnosing and monitoring certain cancers. They can also help in detecting cancer recurrence
- Tumor Markers are commonly proteins produced by the cancerous cells, or sometimes by other body tissue in response to the cancer
- Currently, genetic changes are being investigated, which could help develop markers for certain neoplasms (cancers)
- Tumor Marker Tests are not to be used as stand-alone tests for diagnosing malignancies, which means that they are not diagnostic in nature
- The reason for this being that the tumor markers may be elevated in the case of multiple tumors, or increase with other non-cancerous conditions; their specificity is thus questionable
- It is also possible that an individual with a particular cancer may not have elevated levels of the corresponding tumor marker; their sensitivity is thus questionable
What are the Clinical Indications for performing the Tumor Marker Test?
Indications for Tumor Marker Testing include:
- Diagnosing a particular malignancy: Along with evaluation of medical history, physical exam, tissue exam, and other imaging and blood investigations, the presence of a tumor marker helps in arriving at a diagnosis of certain cancers. E.g. CA-125 is a marker associated with ovarian cancer
- Tumor markers can also be used to screen high-risk groups for the likelihood of a particular malignancy. They cannot be used to screen the general population though. E.g. The use of prostate specific antigen (PSA) to screen men with positive family history of prostate cancer
- Assessing the spread of cancer (metastasis) and to predict outcomes. E.g. HER2/neu positive breast cancers spread faster than other cancers
- In making treatment decisions. E.g. HER2/neu positive breast cancers may respond to targeted therapy
- Evaluating treatment response and detecting any recurrence: Monitoring the levels of tumor markers periodically, can help understand if the treatment is successful (through falling levels of the marker), or is unsuccessful (no changes are noted, or there is an increase in marker levels). If the tumor marker level falls during treatment and subsequently rises, it denotes a recurrence of the cancer
How is the Specimen Collected for Tumor Marker Test?
Sample required: Blood/tissue/bone marrow/urine/body fluid, depending on the cancer being investigated.
- Blood sample is drawn through a needle inserted into the vein (arm)
- Tissue samples may be obtained through surgical means
- Bone marrow sample is obtained via a hollow biopsy needle or through a needle with syringe, introduced into the marrow of the hip bone (commonly)
- Urine sample is collected in clean, sterile containers
Preparation required: Depending on the clinical situation, the physician may advise on any preparation required accordingly.
What is the Significance of the Tumor Marker Test Result?
- The presence of a tumor marker can help in the following manner, with respect to a particular cancer:
- Deciding on the treatment to be followed
- Monitoring treatment response
- Detecting any recurrence
- Predicting the outcome of the cancer
- Depending on the tumor being investigated and the diagnostic value of the tumor marker in that particular scenario, the physician will explain the significance of the result
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.