Content created by Healthline and sponsored by our partners.​ ​ Learn​ ​more

10 Words You Should Know: Non-small Cell Lung Cancer

Medically reviewed by Christina Chun, MPH on August 7, 2017Written by Talia Aroshas and Kristen Garafano on July 31, 2017


Whether you or your loved one has been diagnosed, non-small cell lung cancer (NSCLC) and the many terms related to it can be very overwhelming. Trying to keep up with all the words your doctor tells you can be difficult, especially in addition to the emotional impact of cancer.

Here are 10 words to know about NSCLC that you may encounter as you make your way through testing and treatment.

Programmed death-ligand 1 (PD-L1)

PD-L1 testing measures the efficiency of certain targeted therapies (typically immune-mediated) for those with NSCLC. This helps doctors recommend the best second-line treatment options.

Back to word bank

Epidermal growth factor receptor (EGFR)

EGFR is a gene that is involved in cell growth and division. Mutations of this gene are associated with lung cancer. Up to half of all lung cancer cases have a gene mutation present.

Back to word bank

T790M mutation

T790M is an EGFR mutation seen in about half of all drug-resistant NSCLC cases. The mutation means there is a change in the amino acids, and it affects how someone will respond to therapy.

Back to word bank

Tyrosinse-kinase inhibitor (TKI) therapy

TKI therapy is a type of targeted treatment for NSCLC that blocks the activity of EGFR, which can keep cancer cells from growing.

Back to word bank

KRAS mutation

The KRAS gene helps regulate cell division. It’s part of a group of genes called oncogenes. In the instance of mutation, it can turn healthy cells into cancerous ones. KRAS gene mutations are seen in about 15 to 25 percent of all lung cancer cases.

Back to word bank

Anaplastic lymphoma kinase (ALK) mutation

An ALK mutation is a rearrangement of the ALK gene. This mutation occurs in about 5 percent of NSCLC cases, most commonly in those with the adenocarcinoma subtype of NSCLC. The mutation causes lung cancer cells to grow and spread.

Back to word bank


Adenocarcinoma is a subtype of NSCLC. It tends to grow slower than other types of lung cancer, but this varies. It’s the most common type of lung cancer seen in nonsmokers.

Back to word bank

Squamous cell (epidermoid) carcinoma

Squamous cell carcinoma is a subtype of NSCLC. Many people with this subtype of lung cancer have a history of smoking. The cancer begins in squamous cells, which are cells located inside the lung airways.

Back to word bank

Large cell (undifferentiated) carcinoma

Large cell carcinoma is a subtype of NSCLC that can appear in any part of the lung. It’s usually harder to treat because it grows and spreads quickly. It accounts for about 10 to 15 percent of lung cancers.

Back to word bank


Immunotherapy is a newer treatment for cancer that uses a person’s immune system to help the body attack cancer cells. It can be used to treat some forms of NSCLC, especially in people whose cancer has returned after chemotherapy or another treatment.

Back to word bank

CMS Id: 129271