Menopausal Hormone Therapy Found Safe for Women with BRCA Mutations

New research has vindicated a long-maligned menopausal treatment, revealing that it doesn’t increase breast cancer risk among women with inherited mutations in the BRCA1 or BRCA2 genes—a finding that could bring relief to thousands of women who have avoided treatment due to safety concerns.

Menopausal hormone therapy (MHT), widely considered a first-line treatment for symptoms like hot flashes, night sweats and vaginal dryness, has been approached with caution by many women with BRCA mutations due to their already elevated cancer risk.

“Unfortunately, there has been a lot of reluctance and misinformation regarding MHT,” explained Joanne Kotsopoulos, a scientist at the Women’s College Hospital Research and Innovation Institute, who presented the findings at this week’s San Antonio Breast Cancer Symposium. “This has caused many women to suffer unnecessarily.”

The comprehensive study analyzed data from 676 matched pairs of menopausal women carrying BRCA1 or BRCA2 mutations, comparing those who used MHT against those who did not. Participants ranged in age from 22 to 76, with an average age of 43.8 years.

BRCA genes normally function as tumor suppressors, repairing damaged DNA and preventing cells from becoming cancerous. When mutations compromise these genes, cancer risk increases substantially, particularly for breast and ovarian cancers.

During the 5.6-year average follow-up period, researchers documented a striking result: 87 breast cancer cases occurred in the MHT-exposed group compared to 128 cases in the non-MHT group—showing significantly lower cancer incidence among hormone therapy users.

Most surprising was the finding that women receiving estrogen-only MHT were 63% less likely to develop breast cancer than their counterparts who did not use hormone therapy. Additionally, none of the women who received a combination of conjugated estrogen and bazedoxifene (a selective estrogen receptor modulator) developed cancer during the study period.

“Although based on smaller numbers, this is definitely an exciting and interesting area for future research,” Kotsopoulos noted. “Hypothetically, conjugated estrogen and bazedoxifene could be used to mitigate breast cancer risk by avoiding progesterone, which is thought to be the breast cancer risk-associated component of MHT.”

The research also revealed no significant differences in outcomes between patients carrying pathogenic BRCA1 or BRCA2 variants, further emphasizing MHT’s safety across different mutation carriers.

This study comes at a pivotal moment in hormone therapy’s controversial history. MHT has faced skepticism since 2002, when research suggested increased risks of cancer and other serious conditions. That study dramatically reduced prescription rates and patient acceptance, despite subsequent research painting a much different picture.

The shifting scientific consensus recently prompted the Department of Health and Human Services to announce the removal of outdated FDA warnings from many hormone treatments used for menopause and perimenopause symptoms.

For women with BRCA mutations, the implications are particularly significant. Many are advised to have prophylactic removal of ovaries and fallopian tubes due to their elevated risk of gynecological cancers—procedures that can trigger early menopause in younger women.

“We cannot simply recommend a drastic surgery for young women without offering a way for them to manage the well-established short- and long-term outcomes of surgical menopause,” Kotsopoulos emphasized. “I believe we should educate patients and their health care providers on how we can safely balance the risks and benefits of MHT use to ensure longevity and improve quality of life.”

Medical experts still advise consistent screening for MHT users, and note that hormone therapy is typically avoided in women with a history of breast cancer due to recurrence risk.

This research represents a significant shift in understanding hormone therapy safety for a vulnerable population, potentially opening doors to improved quality of life for thousands of women who have previously faced limited options for managing debilitating menopausal symptoms.