Hormone replacement therapy may be safe after breast cancer treatment
In women with a history of breast cancer, the use of hormone replacement therapy (HRT) did not increase the risk of breast cancer recurrence or death.
The findings add to a growing body of research examining the effects of HRT on cancer risk.
Due to declining estrogen levels, menopause can cause vaginal dryness, hot flashes, trouble sleeping, and other symptoms. HRT is one of the most effective ways to relieve these effects. It works by increasing estrogen levels throughout the body, in what is called systemic estrogen therapy, or near the vagina, with vaginal estrogen therapy.
But the safety of HRT has been hotly debated.
Most breast cancers depend on the hormone estrogen to grow, says Degrade tripaty at the University of Texas MD Anderson Cancer Center in Houston. Thus, many breast cancer therapies work by reducing or stopping the production of estrogen, which can lead to menopausal-like symptoms.
The concern therefore is that increasing estrogen levels to alleviate these symptoms could increase the risk of breast cancer, particularly in people with a personal or family history of the disease.
Several studies have shown that HRT is associated with an increased risk of breast cancer, although last year an analysis of 300,000 women found that taking HRT to ease menopausal symptoms does not increase the risk of dying prematurely. Previous research has also shown that, in people who have had breast cancer, HRT can increase the risk of recurrence.
To further investigate the risk of recurrence, Søren Cold at Odense University Hospital in Denmark and colleagues collected data on 8,461 postmenopausal women in Denmark who had been diagnosed with early-stage breast cancer between 1997 and 2004 and received treatment. Of these, 1957 subsequently used vaginal estrogen therapy and 133 used systemic hormone therapy alone or with vaginal estrogen therapy. Prior to cancer treatment, none had used HRT.
After 10 years, 15.4% of those using vaginal estrogen therapy and 17.1% of those using systemic hormone therapy saw their cancer recur, compared with 19.2% of those using no treatment. There was no association between HRT use and death.
Women who used vaginal estrogen therapy with a class of drugs called aromatase inhibitors, which shut down estrogen production, were more likely to experience a recurrence, but did not have a higher risk of premature death. There was no increased risk of recurrence in women who used vaginal estrogen therapy alongside tamoxifen, which selectively blocks estrogen in breast cells.
“I think the reason we’re seeing a worse effect with aromatase inhibitors is that by replacing estrogen you’re directly counteracting how aromatase inhibitors work,” says Tripathy, who didn’t participate. to this research.
” I do not think so [these results are] conclusive enough to tell someone they can safely use these estrogen products,” says Tripathy, noting that the study size was quite small, especially for those using systemic hormone therapy. But for people who’ve had breast cancer, he says “if you absolutely have to use an estrogen replacement, you should probably take tamoxifen rather than an aromatase inhibitor.”
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