This is the most common type of breast cancer.
Breast cancers can be categorized in a number of ways, one of which being receptor status. This refers to certain proteins on the surface of cells that “receive” things (such as hormones) to fuel the growth of the cancer.
“Think of [receptors] as little baseball mitts that sit on the surface of the cell,” says Amy Tiersten, MD, hematologist and oncologist at Mount Sinai Hospital in New York City. There are three types of receptors that could potentially be on a breast cancer cell: estrogen, progesterone, and HER2/neu.
What Is Hormone Receptor-Positive Breast Cancer?
If breast cancer cells have either many estrogen or many progesterone receptors, this is categorized as hormone receptor-positive breast cancer. This means that the breast cancer is being fueled by either estrogen (ER-positive) or progesterone (PR-positive)—or in many cases, both.
If the cancer cells have neither receptor, this is known as hormone receptor-negative. This might mean they have an overexpression of the HER2/neu protein instead (HER2-positive breast cancer) or they have none of the receptors (triple-negative breast cancer).
Here’s why doctors care about receptor status: Many of the treatments for breast cancer are catered toward the receptor status, so knowing what your receptor status is can help you and your doctor find the most effective treatment for your specific subtype of breast cancer.
Treatments for Hormone Receptor-Positive Breast Cancer
The mainstay of treatment for hormone receptor-positive breast cancer is anti-estrogen medications. There are different types that inhibit the effect of hormones on the cancer cell in various ways.
For example, one type of hormone therapy for breast cancer “blocks the cell’s estrogen receptor from interacting with whatever estrogen is in a woman’s body,” while another kind “actually lowers the amount of estrogen in the person’s body and starves these cells that are dependent upon estrogen to live,” says Dr. Tiersten.
A newer category of drugs that is effective against hormone receptor-positive breast cancer is CDK4/6 inhibitors, which are commonly used for more advanced, metastatic breast cancers. They are used in combination with anti-estrogen therapy and can prolong the effectiveness of the treatment, in order to keep the disease from progressing.
Dr. Tiersten is a professor of medicine, hematology, and medical oncology at the Icahn School of Medicine at Mount Sinai. She sees patients at the Dubin Breast Center.
00:00:00.867 --> 00:00:01.732
00:00:01.733 --> 00:00:05.766
Breast cancers that express either the estrogen receptor
00:00:05.767 --> 00:00:08.499
or the progesterone receptor on the surface of the cell
00:00:08.500 --> 00:00:11.999
are considered hormone receptor-positive breast cancers.
00:00:12.000 --> 00:00:17.032
That's very important because the role of anti-estrogen medications
00:00:17.033 --> 00:00:21.499
plays a very big role in the treatment of that type of breast cancer.
00:00:21.500 --> 00:00:24.566
00:00:24.567 --> 00:00:27.732
There are several different subtypes of breast cancer
00:00:27.733 --> 00:00:31.332
and that is dictated by which receptors
00:00:31.333 --> 00:00:33.332
are on the surface of the breast cancer cell.
00:00:33.333 --> 00:00:35.532
So there are three possible receptors.
00:00:35.533 --> 00:00:37.632
Receptors, think of them as like little basemall mitts
00:00:37.633 --> 00:00:39.732
that sit on the surface of the cell.
00:00:39.733 --> 00:00:42.866
There's the estrogen receptor, the progesterone receptor,
00:00:42.867 --> 00:00:45.866
and then there's a protein called HER2/neu.
00:00:45.867 --> 00:00:49.832
The hormone receptor-positive type, the cancers that have those receptors,
00:00:49.833 --> 00:00:53.332
can respond to anti-estrogen medications.
00:00:53.333 --> 00:00:58.132
About 25 percent of breast cancers overexpress the HER2 protein.
00:00:58.133 --> 00:01:00.399
Those are considered HER2-postiive breast cancers,
00:01:00.400 --> 00:01:04.532
and it's an important thing to know because there are certain targeted therapies
00:01:04.533 --> 00:01:06.399
toward the HER2 receptor.
00:01:06.400 --> 00:01:09.599
The anti-estrogens are really the most effective
00:01:09.600 --> 00:01:10.932
and important part of the treatment.
00:01:10.933 --> 00:01:13.066
They're really the mainstay of treatment,
00:01:13.067 --> 00:01:17.199
and chemotherapy's sort of more icing on the cake in that setting.
00:01:17.200 --> 00:01:19.732
So there are certain anti-estrogen medications,
00:01:19.733 --> 00:01:25.732
such as tamoxifen, which is a drug that blocks the cell's estrogen receptor
00:01:25.733 --> 00:01:30.532
from interacting with whatever estrogen is in a woman's body.
00:01:30.533 --> 00:01:34.332
The aromatase inhibitors are a different form of anti-estrogen medication
00:01:34.333 --> 00:01:38.399
that actually lower the amount of estrogen in the person's body
00:01:38.400 --> 00:01:43.099
and starves these cells that are dependent upon estrogen to live.
00:01:43.100 --> 00:01:45.632
There are other forms of anti-estrogen medications
00:01:45.633 --> 00:01:50.766
that are used in more advanced hormone receptor-positive breast cancer,
00:01:50.767 --> 00:01:55.666
and there are new categories of drugs called CDK4/6 inhibitors,
00:01:55.667 --> 00:02:00.699
which appear to prolong the amount of time that a woman would respond
00:02:00.700 --> 00:02:03.732
to a particular anti-estrogen medication.
00:02:03.733 --> 00:02:10.232
Those drugs that appear to prolong the cell's sensitivity
00:02:10.233 --> 00:02:13.799
to anti-estrogen medications are now being studied
00:02:13.800 --> 00:02:18.932
for earlier stage breast cancer that's hormone receptor-positive.
00:02:18.933 --> 00:02:25.067
Breast cancer HER2 status. Atlanta, GA: American Cancer Society, 2019. (Accessed on December 18, 2019 at https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-her2-status.html.)
Breast cancer hormone receptor status. Atlanta, GA: American Cancer Society, 2019. (Accessed on December 18, 2019 at https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-hormone-receptor-status.html.)
CDK4/6 inhibitors for treatment of metastatic breast cancer. Susan G. Komen. (Accessed on December 18, 2019 at https://ww5.komen.org/BreastCancer/CDK46inhibitorsfortreatmentofmetastaticbreastcancer.html.)