Glossary of medical terms

You may hear these common medical terms and phrases when talking with your healthcare team about HER2+ breast cancer or stomach cancer


Adjuvant treatment

Adjuvant treatment is a treatment for early breast cancer that is given just after, and complementary to, the main treatment (usually surgery). For HER2+ breast cancer, this may include radiation treatment, traditional chemotherapy, hormonal treatment, and/or targeted treatment.


Breast cancer

Cancer that forms in the breast tissues, such as the lining of the milk ducts or in the milk glands. Breast cancer occurs in both men and women, although it is rare in men.


Cancer cell

A cell that divides and reproduces abnormally with uncontrolled growth. This cell can break away, travel to other parts of the body, and then set up at another site. This process is referred to as metastasis.


Treatment that uses drugs to stop the growth of cells (including cancer cells), either by killing the cells or by stopping them from dividing.


Early breast cancer (EBC)

Early breast cancer is breast cancer that has not spread to other parts of the body.

Echo scan

An ultrasound image of the heart; also called an “echocardiogram.”



Of or relating to the stomach.

Gastric cancer

Cancer in the lining of the stomach. Also called “stomach cancer.”


Gastroesophageal junction, where the esophagus meets the stomach.


HER2-positive (or HER2+)

Cancer cells that have too many HER2 receptors are considered HER2-positive. HER2 is a type of protein that tells cells to grow and divide. HER2 is found on the surface of cells in everyone, but cancer cells with too many HER2 receptors can grow and divide too quickly.

HER2 receptor

Human epidermal growth factor receptor 2. HER2 helps cells grow and is found on the surface of both normal cells and cancer cells.


A cancer treatment that targets HER2 receptors.

Hormonal therapy

A type of cancer treatment that helps fight tumors that thrive on hormones like estrogen or progesterone by acting on hormone receptors in tumor cells, or by decreasing the amount of estrogen available to bind these receptors.


Intravenous (IV) infusion

Also known as an IV infusion, this is a way of delivering medication slowly into the bloodstream through a vein or port.


Lymph nodes

Small, bean-shaped organs that store white blood cells and help remove cell waste, germs, and other harmful substances from the body.


Metastatic cancer

Cancer that has spread to other parts of the body, such as the lungs, liver, or bones; sometimes called “advanced” cancer.

Monoclonal antibody

A molecule that is made to target specific cancer cells and may affect normal cells.

MUGA scan

A commonly used test that takes a moving picture of your heart pumping blood, it requires an injection of a nontoxic radioactive substance.



An implanted device through which blood can be taken and medication can be given without repeated needle sticks; also called a “port-a-cath.”


Radiation therapy

A type of cancer treatment that uses high-energy rays to kill cells and/or shrink tumors.


Subcutaneous (SC) injection

Also known as an SC injection, this is a way of delivering a medication under the skin.


Targeted treatment

In HER2+ cancer, targeted therapy is a type of medicine that is designed to attack specific cancer cells, but may also affect healthy cells.


An abnormal mass of tissue that comes from the overgrowth of cells.