Back to top

Decoding Lung Cancer Terminology

 
The treatment planning process can often be confusing for people living with lung cancer and their families. Understand the journey from testing and diagnosis to treatment in non-small cell lung cancer (NSCLC) with this easy-to-use glossary.
TERMDEFINITIONTERM IN A SENTENCE
TESTING AND DIAGNOSIS
TESTING AND DIAGNOSIS
BIOMARKER
A tumor biomarker is a molecule that indicates the presence of a change in a tumor cell’s genes that may be related to the development or spread of cancer. A biomarker may help a doctor choose a specific treatment plan for an individual patient based on the characteristics of their cancer. 1,2

Also referred to as molecular marker.
Scientists are studying biomarkers in order to better understand how lung cancer develops and how best to treat it.
BIOPSY
The removal of a sample of tissue from a patient to look at the presence, cause or extent of a disease.3
In order to better understand my condition, my doctor performed a biopsy by removing a piece of my tumor.
COMPANION DIAGNOSTIC
A test or measurement for a biomarker to help doctors predict whether a patient is likely to benefit from a particular type of medicine.4
The treatment my friend is taking was approved by the FDA with a companion diagnostic to help identify patients who may eligible for that treatment.
DNA
The hereditary material in humans and almost all other organisms found within cells.5
Each person’s DNA is unique and is what distinguishes a person from another.
GENETIC MUTATION
A change in DNA that makes up a gene. Some genetic mutations are inherited and some develop over time. Changes in DNA that develop over time in lung cells can result from exposure to factors in the environment, although sometimes there is no clear cause. 6,7

Also referred to as genetic alteration, genetic insertions or genetic rearrangement.
My doctor explained to me that my cancer is caused by a genetic mutation, or a change in my DNA.
HISTOLOGY
The study of tissues and cells under a microscope. Small cell lung cancer (SCLC) histology and non-small cell lung cancer (NSCLC) histology are the two main types of lung cancer histology. NSCLC is made up of different histologies; adenocarcinoma, squamous cell carcinoma, and/or large cell carcinoma.8
The histology of my tumor helped my doctor diagnose my lung cancer as adenocarcinoma of the lung.
MOLECULE
A molecule is the smallest particle in a chemical element or compound. Molecules are made up of atoms that are held together by a chemical bond. 9
Doctors may look at a biomarker, which is a particular type of molecule, to determine if the cancer is being caused by a mutation or other genetic change.
MOLECULAR TESTING
A process that allows doctors to look inside tumor cells for gene mutations or changes that may have caused them to be cancerous. This type of test helps a doctor develop a treatment plan for a patient. 10

Also referred to as biomarker testing, tumor marker test, molecular profiling or mutation profiling.
When I was diagnosed with lung cancer, my doctor recommended that I get a molecular test in order to understand what treatment options might be appropriate.
PLAN
PLAN
ALK
The Anaplastic Lymphoma Kinase (ALK) gene can be found in everyone’s DNA. Sometimes the ALK gene can attach to another gene and change the way each gene normally functions. This is called an ALK gene rearrangement and can contribute to cancer-cell growth and tumor survival. This change occurs in 3-5% of NSCLC cases. 11, 12, 13
After biomarker testing, my doctor confirmed that my lung cancer was ALK-positive, meaning that my cancer has a rearranged ALK gene.
EGFR
Epidermal Growth Factor Receptor (EGFR) is a gene involved in making cells grow and multiply. EGFR mutations are believed to cause cells to multiply more than normal. The EGFR gene mutation occurs in about 10% of NSCLC patients, and nearly half of lung cancer cases in people who never smoked. 14,15
After biomarker testing, my doctor confirmed that my lung cancer was EGFR-positive, meaning that my cancer has an EGFR mutation.
FIRST-LINE TREATMENT
The first treatment that a doctor prescribes to a patient for a disease such as NSCLC. If the first-line treatment doesn’t work or it causes severe side effects, other treatment may be added or used instead.16

Also referred to as initial treatment.
My doctor prescribed my first-line treatment after I was initially diagnosed with lung cancer.
KRAS
Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) is a gene that helps cells communicate with each other, but if mutated can cause the development of many types of cancer. The KRAS gene is mutated in about 25% of NSCLC adenocarcinoma cases. 17, 18,19

Also referred to as Kras, K-RAS, or KRAS2.
After I had testing, my doctor confirmed that my lung cancer was KRAS-positive, meaning that my cancer has an altered KRAS gene.
METASTASIS
The process by which cancer cells spread from the primary site, or place where it started, to other places in the body. 20

Also referred to as stage 4 or advanced.
The doctor explained that my cancer was metastatic because it had spread from my lungs to another part of my body.
ROS1
The ROS1 gene can be found in everyone’s DNA. Sometimes the ROS1 gene can attach to another gene and change the way each gene normally functions. This is called a ROS1 gene rearrangement and can contribute to cancer-cell growth and tumor survival. This change occurs in approximately 1% of NSCLC cases. 21
After biomarker testing, my doctor confirmed that my lung cancer was ROS1-positive, meaning that my cancer has an altered ROS1 gene.
SECOND-LINE TREATMENT
Treatment that is usually started after the first treatment (also known as first-line treatment) or set of treatments doesn’t work, has stopped working or has caused side effects that cannot be tolerated. 22
After my tumor stopped responding to my first-line treatment, my doctor prescribed a second-line treatment for my lung cancer.
TREAT
TREAT
BIOMARKER- DRIVEN THERAPY
A type of treatment that is designed to block the action of cancer-causing genes or proteins. For people whose tumors test positive for a certain biomarker, it may be possible to base their treatment plan on this particular biomarker. 23

Also referred to as targeted therapy.
After Anthony’s doctor got his biomarker test results back, the doctor prescribed a biomarker-driven therapy.
CHEMOTHERAPY
A cancer treatment that works by stopping or slowing the growth of dividing cancer cells. 24
My doctor suggested chemotherapy to treat my lung cancer to help reduce the size of my tumor and prevent spreading.
IMMUNOTHERAPY
A treatment that uses a patient’s own immune system to help fight cancer. Some immunotherapy treatments boost the body’s immune system, while others help train the immune system to attack cancer cells specifically. 25

Also referred to as I/O, immune-oncology, biologic therapy or biotherapy.
After I had chemotherapy, my doctor thought I might be a candidate for immunotherapy.
PERSONALIZED MEDICINE; PRECISION MEDICINE
Personalized or precision medicine is the process of finding which treatment approaches may work better for certain patients based on genetic, environmental and lifestyle factors.26
A recent news segment reported that precision medicine looks at what treatments may help patients who have a specific gene mutation.
RADIATION THERAPY
The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy) or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, or brachytherapy). 27
My doctor recommended that I undergo radiation therapy to treat my tumor.
SURGERY
A procedure to remove or repair a part of the body or to find out whether disease is present. Surgery is more often an option at the early stages when the cancer has not spread outside the lung, and is typically done to remove a tumor. It is often part of a plan that includes other types of treatments. 28
Since my lung cancer hadn’t spread and was in the early stages, my doctor suggested I have surgery to remove the tumor.
TYROSINE-KINASE INHIBITOR (TKI) THERAPIES
A type of medication that prevents cells from growing and dividing by blocking and stopping cancer-specific molecules and certain cell processes. 29
Rachel’s oncologist said that her tumor may respond to a certain type of treatment called a TKI therapy.
CLINICAL TRIAL
A clinical trial is a research study meant to test new medical approaches. In cancer, a clinical trial may test new ways to treat, find and diagnose cancer, manage symptoms of cancer or side effects from its treatment. 30
My doctor suggested that I enroll in a clinical trial for a new treatment being studied for my specific type of lung cancer.