A Non-Invasive Treatment Is Investigated

Stage 0 breast cancer, also known as ductal carcinoma in situ (DCIS), is when abnormal cells are discovered in the lining of the breast milk duct. DCIS is considered treatable and not invasive.

"The first thing I tell my patients with DCIS is that they have an excellent prognosis. Noninvasive cancer is not life-threatening, but we need to treat DCIS to prevent progression to invasive breast cancer," advises Northwestern Medicine Breast Surgeon Swati Kulkarni, MD.

Early Diagnosis and Treatment Are Key

Treatment for DCIS will differ based on the patient and care plan. However, it can include surgery, radiation or hormone therapy. If it is not found and treated, DCIS can spread outside of its place in the breast milk duct and into surrounding tissue to become invasive breast cancer. "Early detection is so important. I tell everyone to get their annual mammogram. By doing so, I feel like I dodged a bullet," states Jan.

A Potential Option

Ideally, women with DCIS would be able to avoid invasive surgery and/or radiation therapy as treatment for cancer that is not invasive. A clinical trial called the PROMISE study has been underway since 2017 to look at a potential treatment option: the oral medication Duavee®. Led by researchers at Robert H. Lurie Comprehensive Cancer Center of Northwestern University, the study hopes to find out if Duavee can reduce the risk of women with DCIS developing breast cancer.

At this time, Duavee is only approved by the U.S. Federal Drug Administration (FDA) to treat the vasomotor symptoms of menopause, such as night sweats and hot flashes. Duavee is taken by mouth once a day.

Duavee is made up of estrogen and bazedoxifene, unlike other hormone therapies that are a combination of estrogen and progestogens. "A good use for this hormone therapy combination is for women who don't tolerate progesterone or the synthetic progestins very well and experience side effects, such as water retention, or for those who are particularly concerned about breast health," says Northwestern Medicine Center for Sexual Medicine and Menopause Gynecologist Traci A. Kurtzer, MD. "The majority of our patients taking Duavee are very pleased with it."

Additionally, research has linked the combination of estrogen and progesterone to a slightly higher risk for breast cancer when compared with estrogen-only therapy. "Although Duavee has estrogen, it swaps out the progesterone for bazedoxifene, which is a cousin of a well-known breast cancer agent that protects the uterus and decreases invasive cancer risk" says Dr. Kulkarni.

The PROMISE Study

Spearheaded by Dr. Kulkarni, the main goal of the PROMISE study is to find out if Duavee can reduce the risk of developing invasive breast cancer in postmenopausal women with newly diagnosed DCIS. It measures whether Duavee can stop abnormal cells from expanding beyond the lining of the breast milk duct.

When Jan found out she could take part in the study, she recalls, "My doctor said I would be a great candidate, and I trusted her completely. If my breast tissue could help someone else, why not participate?"

Patients in the study receive integrative care and treatment for DCIS at the same time. They take a placebo or Duavee once a day for 3 to 5 weeks before surgery. Either way, they receive their surgery and continue with the treatment plan agreed upon with their care provider.

"Throughout the whole process of being in the study, I felt that there was a group of people around me to support me," Jan reflects. "After participating in the study, I had surgery and my breast tissue came back benign, so I couldn't ask for better results."

An Evolving Field

Treatment options for patients with DCIS are changing and growing. As more data are collected, less invasive treatment methods like oral medications will be better understood and potentially approved by the FDA.

"If we find that Duavee is effective in preventing invasive breast cancer, the medication could offer women with DCIS another option for treatment," states Dr. Kulkarni.

If you are concerned about your breast health, contact your provider. If you have DCIS and would like to participate in this clinical trial, please call 312.695.1102 (TTY: 711) or email promisestudy@northwestern.edu.