What is a Cancer Marker Test?
When there is cancer in the body the cancel cells leaves traces of its existence in different parts of the body such as urine, blood or stool. A cancer marker test also known as a tumor marker test is done to see if an individual has cancer or not. Using a simple blood test, cancer markers may indicate the presence of cancer if there are elevated level.
Is it Accurate?
The use of cancer marker testing is said to be controversial by many experts. The reason is that even if levels are elevated cancer may not be the cause, creating a false-positive. Conversely even if the levels are not elevated cancer may be present, creating a false-negative. Typically if cancer is suspected alternative methods such a biopsy may be performed. Cancer marker tests can be used as a starting point but only thorough cancer screening and ultimately a biopsy can confirm a diagnosis.
Accuracy also varies depending on the test. Cancer marker testing is not a single test but can refer to many tests for many cancer types. Different cancers have different cancer marker tests. Some tests show a high correlation of an individual having cancer while others don’t. Some cancer markers show a great accuracy reported by labs while other markers don’t.
Does it cover all cancer types?
No. While many common cancer types including breast, ovarian, pancreatic, colorectal, prostate, neuroendocrine tumors can be tested for there are many cancers that cannot be tested for. Different tests may be used for different cancer types.
Should I take a Cancer Marker Tests?
If you have a reason to suspect cancer you should immediately consult a doctor. Today more and more health checkups in India are including cancer marker testing. However, the accuracy varies lab by lab and the results are not always conclusive. Therefore, it is best to use this in combination with other clinical factors and tests. In general, it may be best to avoid cancer marker testing unless you suspect cancer and you consult a doctor who recommends it. Cancer markers should not be considered as an alternative to cancer genetic risk testing.
General Guide to Cancer Markers
Wikipedia Tumor Marker (https://en.wikipedia.org/wiki/Tumor_marker#Multiple_Tumor_marker_test)
Cancer Tumor Marker Fact Sheet (https://www.cancer.gov/about-cancer/diagnosis-staging/diagnosis/tumor-markers-fact-sheet#q5)