There is important information about every individual person’s cancer that doctors need to know to recommend the most effective treatment.
The type refers to the specific kind of breast tissue that has become cancerous and started to grow uncontrolled. The most common kinds of cancer occur in duct or lobule tissues in the breast. These are known as “ductal carcinoma” or “lobular carcinoma,” respectively.1
The first line of treatment is usually hormone therapy to stop the tumor growth.
Common hormone therapies include tamoxifen or an aromatase inhibitor.4
Hormone treatments generally work by reducing production of estrogen in the body or blocking estrogen from attaching to the tumor and encouraging its growth.5
HR+ tumors have a lower chance of recurrence, but the tumor can sometimes develop ways to evade therapy.
This tumor sub-type accounts for 1 out of 5 advanced breast cancer cases.3
These tumors can respond to hormone therapy, but HER2+ tumors are more aggressive than HER2- tumors.
A number of medicines are designed specifically to fight HER2+ cancers, mainly by disrupting the cells’ ability to receive growth signals. These include Herceptin, Kadcyla, Nerlynx, Perjeta, Tykerb.6
This tumor subtype does not respond to hormone therapy, since it does not contain a hormone receptor.
Research shows, however, that HR- tumors often respond better to chemotherapy than HR+ ones.7
This type of cancer is often treated with multiple approaches, including chemotherapy and targeted HER2+ therapies.
This type of cancer is also known as triple-negative,” since the tumor does not have receptors for estrogen, progesterone, or human epidermal growth factor 2.
10-20% of breast cancers are triple-negative.8
This kind of cancer is usually treated with a combination of surgery, radiation therapy, and chemotherapy.4
70% of people with triple-negative breast cancer also have the mutation BRCA1, which researchers link with breast cancer. It is also more common among African American women.8
Therapies that can be effective against triple-negative cancer include8:
Neoadjuvant chemotherapy, which is chemotherapy before surgery
Poly ADP-ribose polymerase (PARP) inhibitors, which make cancer cells more likely to die
Immunotherapy medicines like Tecentriq, which enable the immune system to fight the cancer more effectively
Breast Cancer: Introduction. Cancer.Net. October 2018. Available at https://www.cancer.net/cancer-types/breast-cancer/introduction. Accessed January 17, 2019.
Breast Cancer: Stages. Cancer.net. October 2018. Available at https://www.cancer.net/cancer-types/breast-cancer/stages. Accessed January 17, 2019.
Know Your Type. Novartis Pharmaceutical Corporation. April 2018. Available at: http://advancedbreastcancercommunity.org/pdf/asset-library/Know_Your_Type.pdf. Accessed January 17, 2019.
Treatment of Stage IV (Metastatic) Breast Cancer. American Cancer Society. Updated February 1, 2018.
Available at: https://www.cancer.org/cancer/breast-cancer/treatment/treatment-of-breast-cancer-by-stage/treatment-of-stage-iv-advanced-breast-cancer.html. Accessed January 17, 2019.
Treatments for Hormone-Receptor-Positive Breast Cancer. Breastcancer.org. Updated September 15, 2018. Available at: https://www.breastcancer.org/symptoms/diagnosis/hormone_status/treatment_hrpos. Accessed January 17, 2019.
HER2 Status. Breastcancer.org. Updated October 16, 2018. Available at: https://www.breastcancer.org/symptoms/diagnosis/her2. Accessed January 17, 2019.
Treatments for Hormone-Receptor-Negative Breast Cancer. Breastcancer.org. Updated January 26, 2017. Available at:
https://www.breastcancer.org/symptoms/diagnosis/hormone_status/treatment_hrneg. Accessed January 17, 2019.
Triple-Negative Breast Cancer. Breastcancer.org. Updated on December 11, 2018. Available at: https://www.breastcancer.org/symptoms/diagnosis/trip_neg. Accessed January 17, 2019.