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-centre phase 2 clinical trial led by Northwestern Medicine.

Dr. Swati Kulkarni, lead investigator and professor of breast surgery at Northwestern University Feinberg School of Medicine, presented the findings Sunday, June 1, at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.

The trial included 141 postmenopausal women diagnosed with ductal carcinoma in situ (DCIS), a non-invasive form of breast cancer considered a precursor to invasive breast cancer and diagnosed in roughly 60,000 women each year in the U.S.

Participants across 10 sites nationwide were randomised to receive either Duavee — a combination of conjugated oestrogens and bazedoxifene — or a placebo for about four weeks between diagnosis and their scheduled breast surgery.

Kulkarni’s team found the drug significantly reduced cell growth in breast tissue, a key marker of cancer progression.

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.

“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 is a Northwestern Medicine breast surgeon and a member of the Robert H.

Lurie Comprehensive Cancer Centre of Northwestern University.

Kulkarni said 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 — and 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.

While a larger study with longer term follow up is needed before Duavee can be considered for breast cancer prevention, Kulkarni said she was encouraged by the early results, particularly because the drug is already FDA approved and widely available.

Source: Northwestern University