Lung Cancer Biomarkers
What Patients Need to Know
All newly diagnosed non-small cell lung cancer patients should have comprehensive biomarker testing — EGFR, ALK, KRAS, and PD-L1 together determine whether targeted therapy or immunotherapy is the right approach.
Reviewed by XpertPatient Medical Advisory · Updated June 2026 · Sources: NCI · ACS · ASCO · NIH/PMC
Why This Matters
Your lung cancer test results — what they mean
Lung cancer treatment has changed more in the last 15 years than almost any other cancer. Today, a simple test can find a specific mutation in your tumor — and match you to a targeted pill that may work better than chemotherapy.
Every newly diagnosed lung cancer patient should have full biomarker testing before treatment starts. If this hasn’t been done for you, ask your doctor.
The Biomarkers Your Doctor Tests
🔍 Does your cancer have a mutation that a targeted pill can block?
EGFR mutations are found in about 15% of lung cancers. If you have one, targeted pills like osimertinib (Tagrisso) may work better than chemotherapy, with fewer side effects. These are taken at home, once a day.
🔍 Did two genes join in a way that drives cancer growth?
ALK rearrangements are found in about 5% of lung cancers — more common in younger patients and non-smokers. ALK inhibitors like alectinib work very well against ALK-positive tumors.
🔍 Is there a common driver mutation in your tumor?
KRAS is the most common mutation in lung cancer. A specific type called KRAS G12C can now be targeted with sotorasib (Lumakras) — a major recent breakthrough in lung cancer treatment.
🔍 Will immunotherapy work for your cancer?
PD-L1 is a protein that helps cancer hide from your immune system. Testing PD-L1 levels tells your doctor whether immunotherapy drugs like pembrolizumab (Keytruda) are likely to be effective.
🔍 Is a key protective gene damaged?
TP53 normally helps stop cancer from forming. When it’s mutated, the cancer can grow more aggressively. Your doctor uses TP53 status as one of several signals to plan treatment.
Sources: LUNGevity Foundation · NCI · NIH/PMC
Common Questions
Lung Cancer Biomarkers — Frequently Asked Questions
❓ Do all lung cancer patients need biomarker testing?
Yes — if you have non-small cell lung cancer (NSCLC), comprehensive biomarker testing is recommended before any treatment starts. It should include EGFR, ALK, ROS1, KRAS, BRAF, PD-L1, and ideally a full genomic panel.
❓ What if my tumor has no mutations?
About 30–40% of lung cancers don’t have a currently targetable mutation. For these tumors, immunotherapy (based on PD-L1 score) or chemotherapy are the main options. New targeted therapies are being developed constantly — ask about clinical trials.
❓ What is a liquid biopsy?
A liquid biopsy detects cancer DNA floating in your bloodstream from a simple blood draw. It’s useful when getting a tissue biopsy is difficult, or to check whether the cancer has developed new mutations during treatment.
❓ What does ‘comprehensive genomic profiling’ mean?
It means testing your tumor for hundreds of mutations at once, rather than one at a time. This single test can find rare mutations that standard panels miss, potentially opening doors to additional treatment options or clinical trials.
Know Your Biomarkers. Own Your Journey.
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Visit the Lung Cancer Center → Full Biomarkers Guide →
