A small, early study suggests that an experimental combination of testosterone and the aromatase inhibitor Arimidex (chemical name: anastrazole) implanted under the skin (subcutaneously) as a pellet every 90 days helped ease menopausal symptoms in breast cancer survivors. These results were presented at the 2010 American Society of Clinical Oncology (ASCO) Breast Cancer Symposium.
Menopausal symptoms such as hot flashes and night sweats can dramatically reduce quality of life for some women. Breast cancer survivors may experience menopausal symptoms for two reasons. First, many survivors have gone through menopause when they're diagnosed and treated. Second, some breast cancer treatments, including chemotherapy and hormonal therapy, can cause menopausal symptoms in both pre- and postmenopausal women.
Hormone replacement therapy (HRT) is used by some women to ease menopausal symptoms. But research has shown that HRT increases breast cancer risk in women who haven't been diagnosed. HRT also increases the risk of the cancer coming back (recurrence) in women who have been diagnosed. So women with very troubling menopausal symptoms need to weigh the benefits of HRT against these risks.
Earlier research has shown that giving testosterone subcutaneously may ease several menopausal symptoms, including hot flashes, sleep problems, irritability, and fatigue. Using testosterone instead of the female hormones in HRT (estrogen and progesterone) to treat menopausal symptoms in breast cancer survivors seems like a good alternative to minimize the risk of breast cancer recurrence.
Testosterone is considered a male hormone because men have much higher levels of it than women. In men, testosterone is made by the testes and helps maintain:
- bone density
- fat distribution
- muscle strength and mass
- red blood cell production
- sex drive
- sperm production
In women, testosterone is made by the ovaries and the adrenal glands. The enzyme aromatase converts some testosterone to estradiol, an estrogen-type hormone. This estradiol converted from testosterone could increase the risk of recurrence.
Aromatase inhibitors are the most common type of hormonal therapy medicines used to lower the risk of breast cancer recurrence in postmenopausal women diagnosed with early-stage, hormone-receptor-positive breast cancer. Aromatase inhibitors work by blocking aromatase.
To minimize the amount of testosterone converted to estradiol in this study, the researchers combined testosterone with Arimidex in pellet implanted under the skin.
To assess how well the Arimidex-testosterone pellets eased menopausal symptoms, 43 breast cancer survivors (39 had been diagnosed with early-stage breast cancer and four were diagnosed with advanced-stage breast cancer) had a pellet containing testosterone and Arimidex implanted under her skin every 90 days. Most of the women (38) had competed treatment more than 5 years before this study started. The women were followed for 6 months or longer.
- The women reported their menopausal symptoms had eased.
- Estradiol levels, which were measured regularly during the study, remained generally low.
- None of the women had any side effects or complications from the treatment.
- None of the women diagnosed with early-stage breast cancer had a recurrence during the study.
- The cancer didn't grow in three of the four women diagnosed with metastatic breast cancer during the study.
These results are promising, but they are still EARLY results. The researchers hope to do a larger study looking at the benefits and safety of the subcutaneous testosterone/Arimidex pellet.
If you're a breast cancer survivor and are having bothersome menopausal symptoms, talk to your doctor about all your options. Ask how you can minimize your recurrence risk AND relieve your symptoms. Be sure to discuss the pros and cons of currently available HRT options. Research suggests that estrogen-only HRT increases risk less than combination HRT, which contains estrogen and progesterone. If you do decide to take HRT, ask if you can take a lower-dose formula and try to take it for the shortest time possible.
Read more about more about menopausal symptoms in the Breastcancer.org Managing Menopausal Symptoms pages.