Receptors on breast cancer cells impact your treatment options.
The types of breast cancer can refer to a few different things. Doctors can classify breast cancer based on whether or not it is invasive (meaning it has spread to surrounding breast tissue), whether or not it begins in the milk ducts, whether or not it is carcinoma (meaning it begins in the lining of the tissues lining internal organs), and more.
Another way to categorize breast cancer is by receptor status. “There are different subtypes of breast cancer based on what receptors are expressed on the surface of the breast cancer cell. There are hormone receptors, estrogen and progesterone, and then there’s a protein called HER2,” says Amy Tiersten, MD, oncologist at Dubin Breast Center at Mount Sinai Hospital in New York City.
Receptors on breast cancer cells help fuel the growth of cancer tumors. This is important, because if doctors know what’s helping cancer grow, they can use that information to choose a treatment to halt that growth.
“Breast cancers that express either the estrogen receptor or the progesterone receptor on the surface of the cell are considered hormone receptor-positive breast cancers,” says Dr. Tiersten. “Those tend to be more slow-growing and less aggressive types of breast cancer.”
Whether the receptor is estrogen or progesterone, doctors can use anti-estrogen medication (which is called hormone therapy) to treat the cancer and lower the risk of breast cancer recurrence.
HER2-positive breast cancer means the cancer cells contain a receptor for the HER2 protein (sometimes called HER2/neu). This is the case for about 25 percent of all breast cancers.
HER2 stands for human epidermal growth factor receptor 2, and it’s a growth-promoting protein on the outside of all breast cells. However, someone with HER2-positive breast cancer has higher than normal levels of the protein on the cancer cells.
HER2-positive breast cancers “are cancers that used to be considered very aggressive, but nowadays, it’s considered a good thing to have HER2-positive breast cancer because we have incredibly effective, targeted antibodies to that HER2 protein,” says Dr. Tiersten.
Triple-negative breast cancers contain none of these receptors, and they account for 15 to 20 percent of breast cancer diagnoses. Because they lack the known receptors for breast cancer, neither hormone therapy nor targeted therapy is effective against triple-negative breast cancer.
“Triple-negative breast cancers are inherently more aggressive,” says Dr. Tiersten. “At the present time, all we really have for triple-negative breast cancer is your standard traditional chemotherapy.” That said, chemotherapy tends to work more effectively in triple-negative breast cancer than for other types of breast cancer.
Triple-positive breast cancer means the breast cancer cells contain all three receptors. They respond to all of the treatments that target receptors.
“The entire prognosis and treatment plan is completely based on the subtype of breast cancer,” says Dr. Tiersten. “Years ago, we thought of breast cancer as one disease, but biology has moved so far forward that we really tailor the treatment to the specific type of breast cancer.”
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.
00:00:00,000 --> 00:00:02,455
00:00:02,455 --> 00:00:07,447
There are really different behaving types
of breast cancers, and that the presence
00:00:07,447 --> 00:00:11,810
or absence of the receptors really
determine prognosis and treatment.
00:00:11,810 --> 00:00:16,953
And so there are very different diseases
within a breast cancer diagnosis.
00:00:16,953 --> 00:00:22,592
00:00:22,592 --> 00:00:26,588
There are several different
subtypes of breast cancer, and
00:00:26,588 --> 00:00:32,110
that is dictated by which receptors are on
the surface of the breast cancer cell.
00:00:32,110 --> 00:00:35,334
Receptors, think of them as little
baseball mitts that sit on the surface
00:00:35,334 --> 00:00:35,913
of the cell.
00:00:35,913 --> 00:00:38,290
So there are three possible receptors.
00:00:38,290 --> 00:00:41,403
There's the estrogen receptor,
the progesterone receptor.
00:00:41,403 --> 00:00:45,790
The cancers that have those receptors can
respond to anti-estrogen medications.
00:00:45,790 --> 00:00:48,727
And then there's a protein
00:00:48,727 --> 00:00:55,450
We have incredibly effective targeted
antibodies to that HER2 protein.
00:00:55,450 --> 00:01:00,520
They're very targeted because not a lot
of other cells in your body actually have
00:01:00,520 --> 00:01:02,110
00:01:02,110 --> 00:01:06,370
A triple negative breast cancer just
means that none of those three receptors
00:01:06,370 --> 00:01:06,950
00:01:06,950 --> 00:01:08,920
So not that it's triply bad, but
00:01:08,920 --> 00:01:13,600
that there are three possible receptors
which are absent on those cells.
00:01:13,600 --> 00:01:17,326
We really used to consider
breast cancer one disease,
00:01:17,326 --> 00:01:21,214
but biology has moved so
far forward that we really tailor
00:01:21,214 --> 00:01:24,869
the treatment to the specific
type of breast cancer.
00:01:24,869 --> 00:01:30,494
Breast cancer HER2 status. Atlanta, GA: American Cancer Society, 2017. (Accessed on April 9, 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, 2017. (Accessed on April 9, 2019 at https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-hormone-receptor-status.html.)