Cancer Knowledge Center
Biomarkers
What molecular markers mean, how they are tested and how they influence targeted treatment options.
About this topic
Biomarkers are measurable molecular features of a tumour that tell your care team how the cancer is likely to behave and which drugs it may respond to. Modern oncology increasingly treats the biology of a tumour rather than only its location, and biomarker testing is what makes that possible.
This hub explains what biomarker testing is, how tissue and blood tests are performed, and what individual markers such as KRAS, EGFR, HER2, BRCA1/2, PD-L1, MSI and ALK mean for targeted therapy, immunotherapy and clinical trial eligibility.
Featured articles
What Are Cancer Biomarkers and Why Do They Matter?
A complete patient guide to cancer biomarkers: what they are, the main types, how testing works, key examples such as KRAS, EGFR, HER2, BRCA1, BRCA2 and PD-L1, and how results change treatment decisions.
12 min readStart hereKRAS
A patient guide to KRAS mutations in pancreatic, colorectal and lung cancer, covering G12C, G12D and G12V variants, KRAS inhibitors, anti-EGFR resistance and testing.
13 min readStart hereEGFR
A patient guide to EGFR mutations — exon 19 deletion, L858R, exon 20 insertions, T790M resistance — testing, EGFR TKI generations, and lung, colorectal and head and neck cancer.
13 min readLatest articles
All articles in this topic
What Are Cancer Biomarkers and Why Do They Matter?
KRAS
NRAS
Coming SoonBRAF
Coming SoonEGFR
HER2
ALK
ROS1
Coming SoonPD-L1
MSI
TMB
Coming SoonBRCA1
BRCA2
NTRK
Coming SoonRET
Coming SoonMET
Coming SoonFrequently asked questions
Do I need biomarker testing?
For many advanced cancers, guidelines recommend molecular testing before starting drug therapy. Ask your oncologist which panel was ordered and whether results are already available.
What is the difference between a germline and a somatic mutation?
A germline mutation is inherited and present in every cell; a somatic mutation arose in the tumour only. The distinction affects family risk and sometimes drug choice.
Can biomarkers change over time?
Yes. Tumours evolve under treatment pressure, which is why repeat biopsies or liquid biopsies are sometimes performed at progression.
Related topics
Cancer Types
Overviews of common cancer types, how they are staged and what usually shapes treatment decisions.
Treatments
How the main cancer treatment approaches work, what they are used for and what to expect.
Clinical Trials
How research studies work, what the phases mean and how eligibility and consent are handled.
Educational information only. GetOnco is software, not a medical provider, and does not diagnose disease or recommend treatments. Always discuss your situation with qualified healthcare professionals.