Although they are not first-line choices, vaginal estrogen preparations may be safely administered to women with a history of estrogen receptor-positive breast cancer and menopause-related urogenital symptoms.
Committee Opinion No. 659: The Use of Vaginal Estrogen in Women with a History of Estrogen-Dependent Breast Cancer.
Authors: Farrell, R. et. al.
Source: Obstet Gynecol 2016; 127:e93-6.
Supplemental estrogen therapy is very successful in alleviating the menopause-related symptoms of vaginal atrophy. However, there has been consistent concern that providing any estrogen preparation in a woman with a history of estrogen-dependent breast cancer may increase her risk of cancer recurrence. This article is a summary reached by a committee from the American College of Obstetricians and Gynecologists regarding the treatment of menopause-related urogenital symptoms (lower urinary tract infections, vaginal dryness and discomfort, sexual dysfunction) in this specific group.
The group reviewed current research about the effects of vaginal estrogen preparations on breast cancer outcomes. First, they demonstrated that the three most common preparations (cream, ring, pill) have very little effect on circulating levels of estrogen. In fact, when used properly, they do not raise estrogen levels above those of menopausal women. These preparations are not associated with increased recurrence risk in women undergoing breast cancer treatment, or in women with a history of breast cancer.
Specifically regarding estrogen-dependent breast cancer, the committee surmised that vaginal estrogen preparations did not increase breast cancer recurrence rates. They did acknowledge, however, the concern that vaginal estrogen may limit or counteract the effects of aromatase inhibitors: those medications cause significant drops in serum estrogen. Vaginal estrogen preparations raise those levels, although the effect is not permanent and studies have not demonstrated an increase in breast cancer recurrence in patients taking aromatase inhibitors and vaginal estrogen. Vaginal estrogen may be more suitably used in women taking Tamoxifen, as that medication’s effects are via estrogen receptor blockade and not direct reduction of serum estrogen levels.
The Committee makes recommendations for the treatment of menopause-related urogenital symptoms in women with a history of estrogen-dependent breast cancer. First-line choices should consist of nonhormonal treatments, such as lubricants, moisturizers and topical anesthetics. If these approaches have limited or temporary effects, then vaginal estrogen is safe to consider. While current evidence suggests that there is no effect on breast cancer outcomes, women should be advised by their cancer care providers in order to balance the risks and benefits of the medications, and to make an informed decision.