Bold claim upfront: Menopausal hormone therapy may be safer for BRCA1/2 mutation carriers than widely assumed, offering relief from menopause symptoms without amplifying cancer risk. And this is where it gets controversial: the findings come from a carefully designed study that challenges long-standing caution about HRT in high-risk groups.
A multinational investigation examined whether menopausal hormone therapy (HRT) adds cancer risk to women who carry BRCA1 or BRCA2 mutations. The study followed 1,352 menopausal carriers of these genetic variants, splitting them into two groups: about half received hormone replacement therapy, and half did not. Over an average follow-up of nearly six years, the HRT group did not show an increased risk of cancer compared with the non-HRT group.
For many years, millions of women experience menopause symptoms, yet safe and effective treatment options remain limited. HRT has long been the go-to method for symptom relief, but its use declined sharply after the early 2000s due to concerns about potential health harms.
The decline followed results from the Women’s Health Initiative (WHI) trials in 2002, which suggested that HRT in healthy postmenopausal women could raise the risks of blood clots, strokes, and breast cancer. Those findings sent shockwaves through medicine and led to a steep drop in HRT prescriptions. Since then, subsequent research has nuanced the picture: while some studies question the initial conclusions, many experts agree that HRT can be beneficial for appropriately selected patients when prescribed thoughtfully.
Nonetheless, there has been persistent caution around applying HRT to women with specific high-risk genetic profiles, such as BRCA1/2 mutation carriers. The current study, presented at the San Antonio Breast Cancer Symposium by Joanne Kotsopoulos, PhD, of the University of Toronto, aimed to specifically assess the cancer risk associated with HRT in this population—many of whom undergo oophorectomy (ovary removal) to lower ovarian cancer risk and may experience early surgical menopause.
Kotsopoulos emphasized that much of the prior hesitancy stems from extrapolating data from the general population to BRCA mutation carriers. She and colleagues argued that targeted, well-designed observational studies are needed to understand how HRT affects women with BRCA mutations who face different baseline risks.
In the study design, 676 menopausal BRCA1/2 variant carriers were enrolled and compared with an equal number of matched controls sharing the same genetic variants. Matching criteria included specific gene, birth year, and age at menopause onset, ensuring a fair comparison between groups.
Over 5.6 years of follow-up, the incidence of breast cancer was actually higher in the non-HRT group (128 cases, 19%) than in the HRT group (87 cases, 13%), suggesting no added risk from HRT in this population—and possibly even a protective trend in certain circumstances.
Researchers also evaluated different HRT formulations to see if the risk varied with therapy type. Most regimens did not show meaningful differences in breast cancer risk between treated and untreated carriers. Interestingly, estrogen-containing regimens appeared to correlate with a notable reduction in breast cancer risk—about 63% lower during the follow-up period for estrogen users compared with non-users among BRCA mutation carriers.
Importantly, whether a participant carried BRCA1 versus BRCA2 variants did not substantially alter these findings; similar results emerged across both gene groups.
The authors conclude that these data provide a more evidence-based framework for managing menopausal symptoms in women at high genetic risk for breast cancer, particularly those undergoing early surgical menopause. They advocate using these insights to balance the benefits of symptom relief against cancer risk in BRCA1/2 carriers, rather than applying broad general-population assumptions.
Controversial note and open questions for readers: should BRCA mutation carriers be counseled differently about HRT based on this study, or do we need even larger, longer-term trials to confirm safety across diverse populations and longer time horizons? Do these results apply to all types and dosages of HRT, or are there specific regimens that warrant extra caution? How do these findings integrate with ongoing discussions about risk-reducing surgeries and personalized medicine? Share your perspective in the comments.
