Tamoxifen is a selective estrogen receptor modulator and the most commonly used anti-estrogen drug. A medical oncologist can prescribe this drug to a premenopausal or postmenopausal woman, as adjuvant endocrine therapy for ER+ breast cancer. Naturopathic support is most frequently directed towards reducing menopausal-like symptoms, such as hot flashes, vaginal dryness, hair thinning, mood changes and fatigue. While women are on this drug, it is also a great time to optimize nutritional status, improve dietary practices, encourage healthy life-style practices and work on risk reduction strategies. Tamoxifen also has some risk for other more severe side effects such as cancer of the endometrium, blood clots or others.
Aromatase Inhibitor (AI)
In postmenopausal women with ER+ breast cancer, an AI (Letrozole, Examestane or Anastrazole) may be prescribed by a medical oncologist to reduce estrogen levels by blocking enzyme-mediated estrogen synthesis. Treatment with an AIs is associated with an increased risk of bone loss and arthralgia (joint pain). Some studies suggest early breast cancer has a high prevalence of 25-hydroxyvitamin D insufficiency. Low vitamin D might exacerbate bone loss and is associated with worse intensity of arthralgias while on an AI (Ther Adv Med Oncol. 2015 Sep; 7(5): 291–296.). Dr. Moore recommends testing of serum vitamin D levels in patients, especially if they are starting an AI drug. The goals of naturopathic support with AI therapy may include:
- Reduce arthralgias
- Support bone health
- Mitigate menopausal-like symptoms (hot flashes etc)
- Address fatigue and sleep issues
- Address other side effects as needed such as fatty liver, cholesterol levels and others
Fulvestrant is an estrogen receptor antagonist administered by intramuscular injection for patients with ER-positive, HER2-negative, postmenopausal advanced or metastatic breast cancer, and sometimes for women who have had disease progression on other anti-estrogen therapy. If a medical oncologist administers this therapy they will educate you on potential side effects such as hot flashes, fatigue, GI issues, sore throat, infections, pain at the injection site or others. Naturopathic therapies and lifestyle are used to help reduce side effects and support quality of life.