A drug already approved by the FDA to treat menopause symptoms may also help prevent invasive breast cancer, according to new findings from a multi-center phase 2 clinical trial led by Northwestern Medicine. The study examined Duavee, a combination of conjugated estrogens and bazedoxifene, in 141 postmenopausal women diagnosed with ductal carcinoma in situ (DCIS).
Dr. Swati Kulkarni, lead investigator and professor of breast surgery at Northwestern University Feinberg School of Medicine, will present the findings at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago on June 1.
Trial Design and Patient Population
The randomized trial included 141 postmenopausal women across 10 sites nationwide who were diagnosed with DCIS, a non-invasive form of breast cancer considered a precursor to invasive breast cancer. DCIS is diagnosed in roughly 60,000 women each year in the United States.
Participants were randomized to receive either Duavee or a placebo for approximately four weeks between their diagnosis and scheduled breast surgery. This treatment window allowed researchers to assess the drug's biological effects on breast tissue before surgical intervention.
Key Findings
Kulkarni's team found that Duavee significantly reduced cell growth in breast tissue, a key marker of cancer progression. The reduction in cellular proliferation suggests the drug may help prevent the progression from non-invasive to invasive breast cancer.
Unlike other breast cancer prevention drugs, which can cause difficult side effects and lead patients to decline taking medication, Duavee was well tolerated by trial participants. The drug did not affect participants' quality of life during the treatment period.
"What excites me most is that a medication designed to help women feel better during menopause may also reduce their risk of invasive breast cancer," said Dr. Kulkarni, who also serves as a Northwestern Medicine breast surgeon and member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.
Target Patient Population
According to Kulkarni, the women most likely to benefit from Duavee are those at elevated risk for breast cancer due to a personal history of high-risk lesions such as atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), lobular carcinoma in situ (LCIS), or prior DCIS who are also experiencing menopausal symptoms.
These women are typically advised against standard hormone therapies, leaving them with few menopausal treatment options. Duavee may offer a promising alternative for this underserved population who face the dual challenge of managing menopausal symptoms while minimizing breast cancer risk.
Clinical Implications and Future Directions
While the results are encouraging, Kulkarni emphasized that a larger study with longer-term follow-up is needed before Duavee can be considered for breast cancer prevention. However, she noted that the early results are particularly promising because the drug is already FDA-approved and widely available.
The dual benefit of addressing menopausal symptoms while potentially reducing breast cancer risk could represent a significant advancement in women's health, particularly for those at elevated cancer risk who have limited treatment options for managing menopause-related symptoms.
