Hormone Receptor Status in Breast Cancer and How It Affects Your Treatment
Breast cancer treatment plans are often personalized based on your specific stage and type of breast cancer.
The hormone receptor status of breast cancer refers to whether the breast cancer cells are fueled by estrogen and/or progesterone due to special proteins inside the tumor cells, called hormone receptors. When those hormones that naturally occur in the female body attach to hormone receptors, the cancer cells grow. A hormone receptor status is either hormone receptor-positive or hormone receptor-negative.Hormone receptor-positive breast cancer cells have either estrogen (ER) or progesterone (PR) receptors. These breast cancers can be treated with hormone therapy drugs that lower estrogen levels or block estrogen receptors. Hormone receptor-positive cancers tend to grow more slowly than those that are Hormone receptor-negative. Hormone receptor-positive cancers are generally more common in women after menopause.
How Hormone Status Affects Breast Cancer Treatment Options
It is critical that your oncologist knows which hormones if any, are involved in the growth of the breast cancer. They will run some tests that indicate the hormone receptor status and HER2/neu status of the breast cancer tumor. The results then play a large role in the kind of breast cancer treatment that’s recommended. There is typically one of the following four results:
- Estrogen-receptor positive or negative (ER+/-) - The breast cancer cells may or may not have receptors for the hormone, estrogen. ER+ results suggest that the cancer cells may receive signals from estrogen that could promote their growth.
- Progesterone-receptor positive or negative (PR+/-) - The breast cancer cells may or may not have receptors for the hormone, progesterone. PR+ results mean that the cancer cells may receive signals from progesterone that could promote their growth.
- HER2 positive or negative - HER2 (human epidermal growth factor receptor 2) is a protein that appears on the surface of some breast cancer cells and plays a role in how a healthy breast cell grows, divides, and repairs itself. Knowing whether they are present will affect the treatment that’s chosen.
- Triple-negative breast cancer - These breast cancer cells test negative for estrogen receptors, progesterone receptors, and HER2. Triple-negative breast cancer will be treated differently than the other types of breast cancer since hormones are not playing a role in the breast cancer’s growth.
HER2 Status in Breast Cancer
The behavior of breast cancer can be contributed to some genes and the proteins they make. These genes and their proteins can also affect how the disease responds to specific cancer treatments. HER2 (or human epidermal growth factor receptor 2) is a gene that can play a role in the development of breast cancer.
What does it mean to be HER2- negative or positive?
HER2-negative breast cancers do not have an excess of the HER2 gene. These tumors will not respond to therapies that specifically target HER2 receptors.
HER2-positive breast cancers have too much HER2 protein or extra copies of the HER2 gene. Healthy cells have some HER2, but some breast cancer diagnoses have an excess of this protein, signaling the cells to grow and divide quickly. These breast cancers tend to be fast-growing. HER2-positive breast cancer treatment typically includes targeted therapy drugs that slow the growth and kill these cancer cells.
It is typical for your doctor to test your HER2 status to determine if it is playing a role in your cancer so that your doctor can select a medication that addresses HER2-positive patients.
Triple-Negative Breast Cancer
Triple-negative breast cancer is a type of cancer that does not have estrogen receptors, progesterone receptors, or HER2 receptors.
Since triple-negative breast cancer doesn’t show hormone receptors on cancer cells, it most likely won’t respond to breast cancer treatments using hormone blockers to slow the growth of estrogen-positive or progesterone-positive cancers. There's also no significant amount of HER2 protein fueling the cancer, making targeted therapies for HER2 protein ineffective.
Triple-negative breast cancer is typically treated with a combination of treatments that can include surgery, radiation therapy, chemotherapy, and in some cases, immunotherapy. This type of cancer is currently under extensive research to find a combination of therapies that work to battle this typically aggressive type of cancer. If you have been diagnosed with triple-negative breast cancer, you may be offered a clinical trial as part of this significant research effort to find a widely accepted treatment plan.