Biomarkers

Within oncology, biological molecules are those which are produced by the body or tumor in a person with cancer. Biomarker testing can help characterize alterations in the tumor and can be categorized as DNA, RNA, protein or metabolomic profiles that are specific to the tumor.

Biomarker testing for cancer treatment may also be referred to as tumor testing, tumor genetic testing, genomic profiling/ genomic testing, molecular testing/ molecular profiling, tumor subtyping or somatic testing. Biomarker tests can help clinicians decide which cancer treatment will be best suited to a particular patient. Additionally, some cancer treatments, including targeted therapies and immunotherapies, may only work for people whose cancers have certain biomarkers. E.g. individuals with cancer that has certain genetic changes in the EGFR gene can get treatments that target those changes, termed EGFR inhibitors.

There are various types of biomarker tests. Some biomarker tests look for many genes and are termed multigene or panel tests, an example being the Oncotype DX test for detecting breast cancer. Other types of biomarker tests are whole-exome sequencing or whole-genome sequencing. Tests can also look for tumor mutational burden, these are particularly useful for determining if immune checkpoint inhibitors will work for a patient. Lastly, there are biomarker tests that aim to detect a single biomarker.