Biomarker testing, also called genetic testing, molecular testing, or mutation testing, is an important part of your full diagnosis. Biomarkers are biological molecules found in the blood or tissue. Biomarkers can serve as indicators of various types of cancer. Some biomarkers occur because of changes in the genes called mutations.
Learning more about cancer’s biomarkers can be very helpful in understanding more about your type of cancer and the treatment that may work best for you.
But What Is a Biomarker Anyway?
Doctors often test for biomarkers with a biopsy. This is where tissue is removed from a tumor, so it can be tested. Sometimes a doctor will use a blood test, also known as a liquid biopsy. He or she will decide which test is right for you.
Here are common biomarkers you may be tested for if you have metastatic lung cancer:
- Programmed death-ligand 1 (PD-L1)
- Epidermal growth receptor (EGFR)
- Kirsten rat sarcoma (KRAS)
- ROS proto-oncogene 1, receptor tyrosine kinase (ROS1)
- Mesenchymal-epithelial transition (MET)
- Anaplastic lymphoma kinase (ALK)
- B-Raf proto-oncogene, serine/threonine kinase (BRAF)
- Neurotrophic tyrosine receptor kinase (NTRK)
Why should I get tested?
Biomarker testing can determine treatment options that are proven to work for your specific type of stage 4 lung cancer. If your lung cancer tests positive for a biomarker, you and your doctor may discuss targeted therapies, which are treatments designed to block the growth and spread of cancer cells in certain cancers. Learn more about a treatment option available for people with EGFR+ stage 4 lung cancer.
Biomarkers for People Living With Stage 4 Lung Cancer
These are some of the most important biomarkers doctors look for when determining how to treat lung cancer:
PD-L1: up to 19%-100% of cases
PD-L1 (Programmed death-ligand 1) is a protein that hides cancer cells from the immune system. Depending on how much PD-L1 protein is found on a person’s tumor, that can help doctors determine the appropriate treatment.
EGFR: 10%-40% of cases
The EGFR (epidermal growth factor receptor) protein controls cell reproduction and survival. EGFR mutations can lead to tumor growth. As many as 51% of people with EGFR+ NSCLC do not have a history of smoking. The National Comprehensive Cancer Network® (NCCN®) is an alliance of 28 leading cancer centers devoted to patient care, research, and education. NCCN recommends (Category 1) that eligible patients with metastatic non-squamous NSCLC get tested for EGFR biomarkers before starting their first treatment, if clinically possible.*† Learn about treatments designed to target the EGFR mutations.
KRAS: 15%-25% of cases
The KRAS (Kirsten rat sarcoma) gene controls when cells split. KRAS mutations can cause cells to double, grow, and divide.
BRAF: 2%-3% of cases
The BRAF gene is responsible for making a specific protein called B-Raf. This protein helps send chemical signals from the outside of cells to the cell's nucleus. If mutated, BRAF genes have the potential to cause normal cells to become cancerous.
ALK: 1%-12% of cases
The ALK (anaplastic lymphoma kinase) gene causes cells to grow and divide and can cause tumors to grow. The ALK mutation can occur as a mutation in lung cancer whether people have a history of smoking or not. The National Comprehensive Cancer Network® (NCCN®) is an alliance of 28 leading cancer centers devoted to patient care, research, and education. NCCN recommends (Category 1) that eligible patients with metastatic non-squamous NSCLC get tested for ALK biomarkers before starting their first treatment, if clinically possible.*†
MET: 2%-4% of cases
The MET (mesenchymal-epithelial transition) gene is involved in protein creation. If the MET gene changes and/or is strengthened, it can drive growth of tumor cells.
Once you and your doctor know as much as you can about the type of stage 4 lung cancer you have, you can discuss the best treatment options for you. Talk to your doctor about biomarker testing for your stage 4 lung cancer.
*Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Non-Small Cell Lung Cancer V.7.2019. © National Comprehensive Cancer Network, Inc. 2019. All rights reserved. Accessed September 24, 2019. To view the most recent and complete version of the guideline, go online to NCCN.org.
†The NCCN Guidelines® for NSCLC provide recommendations for individual biomarkers that should be tested and recommend testing techniques but do not endorse any specific commercially available biomarker assays.
NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.