From the Guidelines
Patients with cancer should not take estrogen supplements if they have hormonally responsive cancers, but for those with non-hormone-sensitive cancers, estrogen may be considered after careful evaluation. Estrogen can stimulate the growth of hormone-sensitive cancers, particularly breast, endometrial, and ovarian cancers, and thus, estrogen supplements are typically contraindicated for patients with a history of these cancers as they may increase the risk of cancer recurrence or progression 1. However, for patients without hormonally responsive cancers, estrogens may be offered along with other bone-modifying agents (BMAs) when clinically appropriate, as stated in the ASCO clinical practice guideline for the management of osteoporosis in survivors of adult cancers with nonmetastatic disease 1.
When considering estrogen supplements for patients with cancer, it is crucial to weigh the benefits against the risks, particularly the risk of cancer recurrence or progression. For patients experiencing menopausal symptoms who cannot take estrogen, non-hormonal alternatives like selective serotonin reuptake inhibitors (SSRIs), gabapentin, or clonidine may help manage symptoms. The decision to use estrogen supplements should always be made through an individualized risk-benefit assessment with an oncologist and endocrinologist, considering the specific cancer characteristics, treatment history, symptom severity, and overall health status. According to the most recent and highest quality study, the choice of treatment should be based on patient preference, potential adverse effects, quality of life considerations, adherence, safety, cost, and availability 1.
Key considerations in the management of patients with cancer who may require estrogen supplements include:
- Cancer type and stage
- Hormone receptor status
- Time since diagnosis
- Presence of menopausal symptoms
- Availability of non-hormonal alternatives for symptom management
- Individual patient risk-benefit assessment
- Multidisciplinary care involving oncologists and endocrinologists to make informed decisions about treatment choices, as suggested by guidelines for assessing and managing menopausal symptoms after breast cancer 1.
From the Research
Estrogen Supplements and Cancer
- Patients with cancer, particularly breast cancer, should exercise caution when considering estrogen supplements due to the potential risks associated with estrogen-dependent malignancies 2.
- Estrogen replacement therapy is often regarded as potentially dangerous in breast cancer survivors, and alternative treatments such as phytoestrogens have been proposed to alleviate menopausal symptoms 2.
- However, the efficacy of phytoestrogens in improving menopausal symptoms is controversial, and their effects on breast cancer recurrence and mortality are still being studied 2.
Selective Estrogen Receptor Modulators (SERMs)
- SERMs, such as tamoxifen, have been used to treat postmenopausal women with ER-positive breast cancer, but their long-term use is associated with increased risks of endometrial cancer and thromboembolic complications 3.
- Alternative SERMs, such as raloxifene, have been developed and are being evaluated for breast cancer risk reduction, with some studies suggesting they may be a better alternative to tamoxifen due to fewer adverse events 4, 5.
- Raloxifene has been shown to decrease the incidence of osteoporosis and related fractures, as well as offer benefits for breast cancer prevention, making it a potential option for postmenopausal women with osteoporosis who also need breast cancer prevention 5.
Breast Cancer Prevention
- The use of SERMs, such as tamoxifen and raloxifene, has been evaluated for breast cancer risk reduction, with some studies suggesting they may be effective in reducing the incidence of invasive breast cancer 4, 6.
- The Study of Tamoxifen and Raloxifene (STAR) trial showed that raloxifene was equivalent to tamoxifen in preventing invasive breast cancer, but with fewer serious adverse events 5.
- Emerging knowledge about the action of SERMs will provide clues for the design of mechanism-based medicines for breast cancer prevention and treatment 6.