What are Biomarkers?
Biomarkers are substances found in blood, other bodily fluids, or tissues
that can help tell us a lot about certain types of cancers.1
They are like a map or a signature that doctors may use to guide how to treat some
cancers. They may help predict your risk for some cancers or may help tell us if
a treatment may be more or less likely to work.1
Biomarkers have been found for breast, colorectal, lung, and prostate, among other
tumor types.2,3 Some markers have been found only
in one type of cancer so far. Others may be present in different types of cancer.4 For example, the gene HER-2 has been found in breast
and stomach cancer.4
There are many different categories of biomarkers that all have different roles.
Four common categories are found below5:
Detection biomarkers may help doctors find cancer, even in the earliest stages, before it can cause symptoms.
Diagnostic biomarkers may help show if you have cancer or if a cancer is
likely.4 One example is the breast cancer type
1 protein (BRCA1). This is a gene that, if altered (or "mutated"), raises the risk
for developing breast or ovarian cancer.6
Prognostic biomarkers may help doctors understand how cancer may grow, no matter
how it is being treated.4, 5 They also may tell a doctor if the cancer might come back, or recur.4
For example, one test can help doctors know if breast cancer will return after the
tumor has been treated.4 Knowing this may help
doctors decide how they should treat cancer.
Predictive biomarkers are used to help determine the response and side
effects that may result from a treatment.5 This
information helps doctors find out which treatment might be more or less likely
to work. Or they may help a doctor decide on the right dose of a drug.5
Do you have questions? Talk to your doctor. Ask if there is a biomarker for your
type of cancer and if testing may be right for you.