Review on October 23, 2008
Women who take certain medications for breast cancer may want to steer clear of estrogen treatments meant to alleviate vaginal dryness. Research has shown that hormonal replacement therapy that treats menopause and postmenopause symptoms, particularly vaginal dryness, can counteract the benefits of medications used to combat breast cancer in middle-aged women.
A small British study in 2006 found that estrogen replacement medications used to treat dry vagina has the potential to render aromatase-inhibiting breast cancer medication useless. Aromatase inhibitors work by limiting the aromatase enzyme, thus inhibiting estrogen. Estrogen has been linked to the formation of breast cancer.
"In the majority of women [taking aromatase inhibitors], we would anticipate that they would stop the vaginal estrogen therapy." said Dr. Anne Kendall, lead author of the study and a researcher at Royal Marsden Hospital in London.
Several other studies have suggested that even women who do not have breast cancer should think twice before taking hormonal replacement treatment for their dry vagina because of the link between estrogen and breast cancer. A large study in 2002 by the Women's Health Initiative reported the startling link between hormonal replacement therapy and breast cancer.
Vaginal dryness is primarily caused by decreased levels of estrogen. Estrogen helps to keep the vagina healthy tissue healthy by maintaining proper acidic levels, as well as stimulating the production of natural lubricants to ease friction while having sexual intercourse.
The study found that about one in five women undergoing aromatase-inhibitor breast cancer treatment also experience vaginal dryness. Dry vagina in this case is almost always caused by the limitation of the production of estrogen as a result of the aromatase inhibitors, which can cut the level of the major estrogen hormones by as much as 97%.
The researchers suggest that breast cancer patients who are experiencing vaginal dryness and taking aromatase inhibitors should either switch to a different breast cancer drug or cease taking estrogen replace therapy. Many doctors recommend using store bought vaginal lubricant to combat dry vagina instead of medications that carry more potential harmful side effects with them.
- Anne Kendall, M.D., clinical research fellow, breast and biochemistry unit, Royal Marsden Hospital, London, England; Jay Brooks, M.D., chairman, hematology/oncology, Ochsner Clinic Foundation, Baton Rouge, La.; Jan. 26, 2006, Annals of Oncology.
- Hayes, Daniel F. M.D. "Follow-up of Patients with Early Breast Cancer." http://content.nejm.org
- "Hormone therapy: Is it right for you?" mayoclinic.com.