Is Hormone Therapy for Breast Cancer the Right Choice for you?

• Hormone therapy for breast cancer is used to either slow or stop the growth of hormone sensitive tumors. 
• Treatments vary widely, and a large part of what drives the therapy is the hormone receptor status of Estrogen (ER), Progesterone (PR), and Hormonal Epidermal Growth Factor Receptor 2 (HER2).  
• Aromatase inhibitors and other medications are useful in the treatment of breast cancers, but it’s important to understand the differences.  

Breast cancer is the uncontrolled growth of cells in one or both breasts. Although more common in women, men can also get breast cancer. There are different types of breast cancers, depending on the location in the breast in which they begin. Breast cancer can also spread to other parts of the body — commonly the lymph nodes and lungs.  

Hormone Receptor Status

Treatment for breast cancer varies widely, but a huge part of what drives therapy is the hormone receptor status of Estrogen (ER), Progesterone (PR), and Hormonal Epidermal Growth Factor Receptor 2 (HER2). These are naturally occurring hormones in the body that certain breast cancers use as their source of growth. If an individual with breast cancer is positive for any or all of these receptors, hormone therapy can be used.  

Hormone therapy for breast cancer is used to either slow or stop the growth of hormone sensitive tumors. This can be done by either stopping the body from producing these hormones or by interfering with the hormones’ ability to attach to the cancer receptors.  

For example, the ovaries serve as the body’s main source of estrogen. For patients with ER+ breast cancer, an option to stop the body from producing estrogen is removing the ovaries – called an oophorectomy. Another option is using gonadotropin-releasing hormones (GnRH) agonists which interfere with the signals that tell the ovaries to produce estrogen. Examples of GnRH agonists include Zoladex and Lupron.  

Aromatase Inhibitors

Another option is using aromatase inhibitors. Aromatase is an enzyme that helps make estrogen in the ovaries and other tissues. When inhibited, it blocks the body from being able to make estrogen. However, an important consideration with aromatase inhibitors is that it is used the most, and effective, in postmenopausal women. Premenopausal women make too much estrogen for the body to block it effectively. Examples of aromatase inhibitors include Arimidex, Femara, and Aromasin. Arimidex and Femara both temporarily inactivate aromatase, whereas Aromasin permanently inactivates aromatase.  

Another common drug used to treat patients with hormone sensitive breast cancer is tamoxifen. Tamoxifen binds to estrogen receptors, which prevent the estrogen from binding with the cancer cells. Therefore, estrogen cannot aid in the growth of cancer cells, causing them to die.  

Side effects of hormone therapy are common to the side effects that women experience during menopause – including heat flashes, night sweats and vaginal dryness. Another side effect that is seen less commonly is decreased ejection fraction. However, due to the possibility of this while on hormone therapy, patients will get a MUGA or ECHO every three months while on therapy.  

Hormone positive breast cancers have lots of different treatment options, including hormone therapy, chemotherapy, radiation, surgery, and other options. However, not all breast cancers are hormone sensitive.  

When a breast cancer is not hormone sensitive, meaning there are no estrogen, progesterone, or hormonal epidermal growth factor receptors present, this is called triple-negative breast cancer. Triple-negative breast cancer tends to be much more aggressive than hormone sensitive breast cancers. It is not as responsive to treatment, can metastasize quicker, and has a higher risk of reoccurrence. Triple-negative breast cancer cannot be treated with hormone therapy because it will be ineffective.  

Triple-negative breast cancers will almost always need to be treated with chemotherapy; however, chemotherapy is not the only option. Depending on when the tumor is caught, chemotherapy can be used to shrink the tumor to make it resectable. Radiation can also be used as neoadjuvant therapy. 

If the tumor is caught before it has spread to other parts of the body, surgery can be done followed by chemotherapy with an oral drug called Olaparib. Surgery removes the tumor while the chemotherapies are given to ensure that no cancer cells are left in the body. 

If the tumor was caught when it had already spread to other parts of the body, chemotherapy will be the mainstay of treatment. Chemotherapy options used to treat triple-negative breast cancer include gemcitabine, docetaxel, paclitaxel, and Taxotere. When a cancer is not sensitive to hormones, mutations are looked at closely to see if there are drugs available for that mutation. For example, cancers that are BRCA positive can use drugs like cisplatin and carboplatin.  

Immunotherapy

Immunotherapy medications can also be used to treat triple–negative breast cancer. Immunotherapies are drugs that try to build up the body’s immune system to attack the cancer. Pembrolizumab is a common immunotherapy that is given if the cancer cells have a PD-L1 protein. Pembrolizumab is an example of a PD-L1 inhibitor, and it works in the body on the T cells of the immune system. It is a protein that tells the immune system to not attack the healthy cells of the body. However, if cancer cells have PD-L1 proteins, it can stop one’s body from trying to attack the cancer. Therefore, Pembrolizumab is given to prevent this from occurring.    

The Bottom Line

Whether it is a hormone sensitive breast cancer or triple-negative breast cancer – any diagnosis of cancer is scary. As nurses, it is important to be empathetic to patients during this delicate time. Furthermore, patients cannot comprehend things when they feel so overwhelmed, so reiterating and reeducating our patients is important.

Provide the patient with ample time and patience to express their feelings and offer coping strategies if appropriate. A great way to educate the patient while getting chemotherapy is explaining to them what it is used for, but also providing handouts for them to read at their own pace when they get home. Allow the patient to ask questions for the process to be more comfortable, and always offer support to both the patients and their families during the entire experience. 

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