Non-small cell lung cancer (NSCLC) is the most common kind of lung cancer. Between 80 and 85 percent of all lung cancers are this type.

In the past, everyone with NSCLC used to get the same treatment. That might have included surgery, radiation, chemotherapy, or a combination of these treatments.

Cancer is caused by changes in genes that control cell growth and division. These mutations allow cells to grow out of control to form tumors.

Researchers recently discovered that all lung cancers aren’t the same. Cancer cells can be linked to a number of different genetic mutations that help tumors grow.

This discovery led to the introduction of targeted drugs that address specific genetic mutations. Targeted treatments block the signals that help certain lung cancers grow. These drugs improve survival in some people whose lung cancer has gene changes.

Ask your doctor whether you should be tested for NSCLC gene mutations. These tests can help your doctor find the right treatment for you and predict how well you might respond to it.

To find the most effective treatment, your doctor has to first get some information about your cancer.

The tumor type

Different types of cancers respond differently to treatments. NSCLC is divided into three types:

  • Adenocarcinoma starts in mucus-producing cells of the lungs.
  • Squamous cell carcinoma starts in cells that line the airways.
  • Large cell carcinoma can start in any part of the lung. It often grows quickly.

The stage of cancer and how aggressive it is

Early stage NSCLCs haven’t grown beyond the lung. Surgery may be an option for these tumors.

Once the cancer has spread outside the lung, treatments include chemotherapy, targeted therapy, immunotherapy, and radiation.

Some cancers spread faster than others. They need different kinds of treatment.

The tumor’s specific genetic mutations

Mutated genes produce proteins that help cancer cells grow. Targeted drugs block these proteins to prevent the cancer cells from spreading. EGFR, KRAS, and ALK are among the most common genetic mutations doctors test for in lung cancer.

It’s important for your doctor to understand which genetic mutations are in your tumor to choose the right targeted treatment for you.

Analyzing a sample of tissue from your lung, and sometimes the lymph nodes around your lungs, can provide the information needed to guide your treatment. Your doctor will remove this tissue with a needle during a biopsy.

Your doctor sends the tissue sample to a lab for molecular analysis. The lab will screen your cancer for gene mutations and other biomarkers. Knowing which biomarkers you have can help your doctor personalize your treatment.

Your doctor can also order a blood test to detect EGFR mutations.

Certain gene mutations help lung cancers grow and spread. If your test results come back positive for one of these mutations, your doctor can give you a medication that specifically targets the mutation.

Targeted therapies block the pathways that help NSCLC grow and spread. Because these drugs focus on addressing the specific abnormalities that help tumors survive, they’re more effective against cancer than traditional treatments like chemo and radiation.

Targeted drugs may also have fewer side effects.

EGFR

Epidermal growth factor receptors (EGFRs) are proteins on the surface of some cancer cells. They help the cells grow and divide. A mutation in the EGFR gene turns on these receptors, which allows cancer cells to grow faster.

About 10 percent of people with NSCLC and 50 percent of people with lung cancer who never smoked have an EGFR mutation, estimates the Memorial Sloan Kettering Cancer Center.

EGFR inhibitors block the signals that cancers with the EGFR mutation need to grow. This group of drugs includes:

  • afatinib (Gilotrif)
  • dacomitinib (Vizimpro)
  • erlotinib (Tarceva)
  • gefitinib (Iressa)
  • necitumumab (Portrazza)
  • osimertinib (Tagrisso)

ALK

About 5 percent of NSCLCs have a change to the anaplastic lymphoma kinase (ALK) gene. If you have an ALK mutation, your cancer may respond to one of these drugs:

  • alectinib (Alecensa)
  • brigatinib (Alunbrig)
  • ceritinib (Zykadia)
  • crizotinib (Xalkori)
  • lorlatinib (Lorbrena)

KRAS

The KRAS mutation is one of the most common lung cancer gene mutations. It’s found in about 25 percent of NSCLCs. If you have one of these mutations, you may be able to try a new drug in a clinical trial.

MET and METex14

The mesenchymal–epithelial transition (MET) gene is involved in signaling pathways that control cell growth, survival, and spread. The METex14 mutation is a type of MET mutation that’s linked to about 3 to 4 percent of NSCLCs.

Capmatinib (Tabrecta) was recently approved by the Food and Drug Administration as a targeted treatment for the METex14 mutation.

ROS1

About 1 to 2 percent of NSCLCs have this genetic mutation. Usually, cancers that are ROS1-positive test negative for ALK, KRAS, and EGFR gene mutations.

The ROS1 mutation is similar to the ALK mutation. Some of the same drugs treat both mutations, including Xalkori and Lorbrena.

Other gene mutations

A few other NSCLC gene mutations have their own targeted treatments, including:

  • BRAF: dabrafenib (Tafinlar) and trametinib (Mekinist)
  • RET: selpercatinib (Retevmo)
  • NTRK: entrectinib (Rozlytrek) and larotrectinib (Vitrakvi)

Ask your doctor whether your cancer should be tested for gene mutations. The results of these genetic tests can help your doctor find a targeted treatment that’s more likely to work against your specific type of cancer.

Targeted treatments also usually have fewer side effects than chemo or other standard treatments.

If a treatment isn’t available for your specific mutation, you may be able to join a clinical trial of a new drug that’s under investigation.