COMMENTARY
The safety of vaginal estrogen in breast cancer survivors
Currently, more than 3.8 million breast cancer survivors reside in the United States, reflecting high prevalence as well as cure rates for this common malignancy.
When over-the-counter measures including vaginal lubricants and moisturizers are not adequate, vaginal estrogen may be a highly effective treatment for genitourinary syndrome of menopause (GSM), a common condition associated with hypoestrogenism that impairs sexual function and quality of life.
Use of vaginal formulations does not result in systemic levels of estrogen above the normal postmenopausal range. Nonetheless, the U.S. Food and Drug Administration lists a history of breast cancer as a contraindication to the use of all systemic as well as vaginal estrogens.
In premenopausal women, chemotherapy for breast cancer often results in early menopause. Aromatase inhibitors, although effective in preventing recurrent disease in menopausal women, exacerbate GSM. These factors result in a high prevalence of GSM in breast cancer survivors.
Because the safety of vaginal estrogen in the setting of breast cancer is uncertain, investigators at Johns Hopkins conducted a cohort study using claims-based data from more than 200 million U.S. patients that identified women with GSM who had previously been diagnosed with breast cancer. Among some 42,000 women diagnosed with GSM after breast cancer, 5% had three or more prescriptions and were considered vaginal estrogen users.
No significant differences were noted in recurrence-free survival between the vaginal estrogen group and the no estrogen group. At 5 and 10 years of follow-up, use of vaginal estrogen was not associated with higher all-cause mortality. Among women with estrogen receptor–positive tumors, risk for breast cancer recurrence was similar between estrogen users and nonusers.
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Older women who get mammograms risk overdiagnosis
TOPLINE:
Women who continue breast cancer screening after age 70 face a considerable risk for overdiagnosis.
METHODOLOGY:
- Overdiagnosis – the risk of detecting and treating cancers that would never have caused issues in a person’s lifetime – is increasingly recognized as a harm of breast cancer screening; however, the scope of the problem among older women remains uncertain.
- To get an idea, investigators linked Medicare claims data with Surveillance, Epidemiology, and End Results (SEER) data for 54,635 women 70 years or older to compare the incidence of breast cancer and breast cancer–specific death among women who continued screening mammography with those who did not.
- The women all had undergone recent screening mammograms and had no history of breast cancer at study entry. Those who had a subsequent mammogram within 3 years were classified as undergoing continued screening while those who did not were classified as not undergoing continued screening.
- Overdiagnosis was defined as the difference in cumulative incidence of breast cancer between screened and unscreened women divided by the cumulative incidence among screened women.
- Results were adjusted for potential confounders, including age, race, and ethnicity.
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