Many women with a history of estrogen receptor positive breast cancer suffer from genito-urinary symptoms of menopause as a sequela of hormone blockade treatment and from treatment induced menopause. These symptoms include vulvo-vaginal atrophy, vaginal dryness, pain and bleeding, painful intercourse and urinary incontinence.
Despite vulvovaginal atrophy (VVA) being a common side effect, affecting 19–91% of patients treated for onco-gynecological conditions surveys indicate that only about half of oncologists discuss this complication before treatment, and 65–85% report lacking sufficient knowledge about VVA treatment options.
Discussing this complication in advance is beneficial not only for patient awareness but also for prevention. . Consideration of use of local preparations applied before the onset of symptoms may reduce their intensity later. Furthermore, timely interventions not only relieve symptoms but also enhance the quality of life in cancer survivors.***
There is concern about the risks of using vaginal estrogen therapies with this patient population as prior trials have demonstrated risk of recurrence with the use of systemic estrogen therapies. The question remains as to whether local vaginal use of estrogen is safe for this patient population.
A study* was performed comparing 2 large cohorts of women with breast cancer who used vaginal estrogen therapy with women who did not use hormone replacement therapy (HRT). This trial assessed over 49,000 breast cancer patients and demonstrates the safety of vaginal estrogen therapy for this patient population. This cohort study analyzed 2 large cohorts of women aged 40 to 79 years with newly diagnosed breast cancer.
In vaginal estrogen therapy users compared with HRT nonusers, there was no evidence of a higher risk of breast cancer–specific mortality in the pooled fully adjusted model (HR, 0.77; 95% CI, 0.63-0.94).
Results of this study showed no evidence of increased early breast cancer–specific mortality in patients who used vaginal estrogen therapy compared with patients who did not use HRT.
This finding may provide some reassurance to prescribing clinicians and support the guidelines suggesting that vaginal estrogen therapy can be considered in patients with breast cancer and genitourinary symptoms.
A Danish study involving 8461 patients with breast cancer that observed no association between vaginal estrogen therapy and cancer recurrence (adjusted HR, 1.08; 95%CI, 0.89-1.32).
Another 4.5-year cohort study involving 13,479 breast cancer survivors found that local estrogen therapy did not increase the risk of cancer recurrence. Therefore, low-dose local estrogen therapy can be an option when other local treatments are ineffective
Additionally, a case-control study showed no association between vaginal estrogen therapy and breast cancer recurrence among tamoxifen users but did not adjust for cancer stage
Two small cohort studies found no increase in cancer recurrence in patients with breast cancer.
An alternative to vaginal estrogen therapy is Intravaginal Dehydroepiandrosterone (DHEA )therapy. According to the North American Menopause Society, intravaginal dehydroepiandrosterone (DHEA) may be prescribed to women with hormone-dependent cancers when non-hormonal treatments are ineffective. DHEA demonstrates positive effects on symptoms and vaginal pH. DHEA is converted to estrogens intracellularly, avoiding systemic estrogen elevation. It has not been reported to significantly alter active sex hormone levels after 12 weeks of use and does not affect endometrial cells. However, since estrogen is a metabolite of DHEA, caution is advised when prescribing it to women with a history of hormone-sensitive cancer.***
Use of phyto-estrogen vaginal preparations derived from plant sources has not demonstrated significant efficacy in this patient population.
For a comprehensive discussion of assessment and management see” Vulvovaginal Atrophy Following Treatment for Oncogynecologic Pathologies: Etiology, Epidemiology, Diagnosis, and Treatment Options.” ***
Selected References
*JAMAOncol.2024;10(1):103-108. doi:10.1001/jamaoncol.2023.4508
Published online November 2, 2023.
** Le Ray I, Dell’Aniello S, Bonnetain F, Azoulay L, Suissa S. Local estrogen therapy and risk of breast cancer recurrence among hormone-treated patients: a nested case-control study. Breast Cancer Res Treat. 2012;135(2):603-609.
***Narutytė R, Žukienė G, Bartkevičienė D. Vulvovaginal Atrophy Following Treatment for Oncogynecologic Pathologies: Etiology, Epidemiology, Diagnosis, and Treatment Options. Medicina (Kaunas). 2024 Sep 27;60(10):1584.
The 2022 Hormone Therapy Position Statement of The North American Menopause Society” Advisory Panel. The 2022 hormone therapy position statement of The North American Menopause Society. Menopause. 2022;29(7):767- 794.