Women report having similar quality of life whether randomized to active monitoring or surgery for low-risk ductal carcinoma in-situ (DCIS) after two years of follow-up.
In the first large phase 3 randomized clinical trial in the U.S. to look at different management strategies for low-risk DCIS, Dana-Farber Cancer Institute investigators found that the overall lived experience of women randomized to active monitoring is similar to that of those selected to follow the current guideline for care, which is surgery with or without radiation. Health-related quality of life, anxiety, depression, worries, and symptom trajectories were comparable regardless of the treatment received during two years of follow-up.
The findings are being presented on Dec. 12 at the 2024 San Antonio Breast Cancer Symposium by breast oncologist and first author Ann Partridge, MD, MPH, of Dana-Farber Cancer Institute, who is Interim Chair of Medical Oncology at Dana-Farber. They are being presented in collaboration with the primary outcome of the study, led by E. Shelley Hwang, MD, of the Duke Cancer Institute, which demonstrated that invasive disease rates were also comparable at two years.
"These results suggest that in the short term, active monitoring is a reasonable approach to management of low-risk DCIS," says Partridge. "If longer term follow-up supports the safety of active management from a cancer outcomes standpoint, this approach could be considered as an option for women with this condition."
DCIS is often called "stage-zero" breast cancer and involves abnormal cells within the milk ducts. It sometimes progresses to invasive cancer and accounts for approximately one in five new breast cancer cases in the U.S. The disease affects more than 50,000 women each year.
Most women with DCIS undergo surgery to remove part or all of the breast. An estimated 25 to 68 percent of women who undergo breast surgery are at risk of developing persistent pain, which could lead to mobility restrictions or psychological distress. Not all DCIS cases will progress to invasive breast cancer, so many women wonder if surgery is necessary.
Active monitoring is an alternative to surgery and radiation that involves routine mammograms to check for changes in the breast. The COMET study is the first to compare the two approaches and assess both safety and quality of life concerns.
In terms of safety, after two years of follow up, the rate of invasive cancer in women in the surgery group was 5.9%, compared to 4.2% in women who did active monitoring.
"These findings help to create a path forward to reduce some of the collateral effects of breast cancer screening, so the results are helpful for people with high-risk disease but don't harm the patients with low-risk disease," says Hwang, who is vice chair of research in Duke's Department of Surgery. "It's all about building up the knowledge base so women can make smart, evidence-based decisions about their health."
"These early safety results are encouraging," says Partridge. "But it is also critical that we understand how women feel when they are living with this 'watch and wait' approach and how it impacts their overall quality of life."
Patient quality of life refers to an individual's emotional, social, and physical well-being, and their ability to function in the ordinary tasks of living. Prior research has suggested that some women with DCIS experience levels of anxiety and fears of recurrence that are similar to that of women with a history of invasive breast cancer.
The phase 3 study enrolled 957 patients ages 40 and up, at more than 80 sites across the country. After biopsy and confirmation of DCIS, they were randomized to either active monitoring or surgery with or without radiation. Most women in both groups also received endocrine therapy to block the estrogen hormone, which often fuels cancer cells.
Over two years, the investigators asked patients to report on quality of life, anxiety, depression, worries about DCIS, and symptom trajectories via surveys that employed validated quality of life measures. Patients filled out surveys prior to randomization, at six months, one year, and after two years.
Responses were comparable between groups, though the group assigned to guideline-concordant care reported transient arm movement problems and breast pain at six months and one year.
"Fortunately, the overall health-related quality of life, anxiety, depression, worries, and symptom trajectories were comparable regardless of the treatment received during two years of follow-up," says Partridge.
Funding for this study was provided by the Patient-Centered Outcomes Research Institute, the Breast Cancer Research Foundation, the Rising Tide Foundation, the National Cancer Institute of the National Institutes of Health, the University Cancer Research Fund of North Carolina, and Alliance Foundation Trials.
