Important Terms Every Breast Cancer Patient Should Know

May 24, 2017

Important terms breast cancer patients should know
Rachel Freedman, MD, MPH

After a breast cancer diagnosis, it can sometimes be hard to wrap one’s mind around all of the terminology used by doctors and nurses. In fact, a recent study from Dana-Farber Cancer Institute found a significant lack of knowledge among breast cancer patients about the basic characteristics of their disease, including how advanced it is (stage), the grade, and the subtype (e.g. whether it is hormone receptor-positive or HER2-positive).

The study surveyed 500 women in the California Cancer Registry who had early-stage breast cancer. Between 56-58 percent of women knew the correct stage and receptor status of their tumor, and just 20 percent knew the grade. Only 8 percent of the women correctly reported the stage, grade and hormone status of their tumor.

“We were really surprised by the results,” says Rachel Freedman, MD, MPH, the first author of the report. Freedman is a medical oncologist in the Susan F. Smith Center for Women’s Cancers at Dana-Farber. Freedman plans to continue studying how knowledge may impact whether patients receive and complete care for their cancers.

A tumor’s stage, grade and receptor status play important roles in determining an effective treatment plan for patients. Below is more information on these important terms breast cancer patients should know:


The stage of disease indicates how advanced the tumor is. It is based on the size and location of the tumor, as well as how much it has spread to lymph nodes or other parts of the body. Diagnoses can range from Stage 0 to Stage 4, and, in general, the higher the number, the more advanced the disease is.


The grade of a tumor is an indication of how quickly it is likely to grow and spread. In general, low-grade tumors grow slowly and higher-grade tumors grow more rapidly. The grade is assigned based on the how the tumor cells look under a microscope; low-grade tumor cells resemble normal cells more closely than high-grade tumor cells do.

Hormone receptor status

Breast cancer cells can sometimes carry receptors for estrogen or progesterone hormones. If a tumor carries estrogen receptors, it is called estrogen receptor (ER) positive, and if it carries progesterone receptors, it is called progesterone receptor (PR) positive. The hormone receptor status of a tumor can affect a patient’s treatment plan. If a tumor is hormone-positive, therapy may include medications that block hormone signaling or reduce the body’s natural estrogen production, such as tamoxifen or medications called aromatase inhibitors.


Like hormone receptors, the HER2 protein, also called Human Epidermal Growth Factor Receptor 2, can also be found on the surface of breast cancer cells in some cancers. If a tumor has higher than normal amounts of this protein, it may be treated with drugs that target HER2, such as trastuzumab (or Herceptin).

If a tumor does not have an estrogen receptor, progesterone receptor, or HER2, it is known as triple-negative breast cancer. This type of breast cancer may be more aggressive and chemotherapy is often recommended for patients with early-stage disease.