By Nancy Lapid
(Reuters) – Early results from a clinical trial appear to confirm that most women with the precancerous breast condition known as ductal carcinoma in situ (DCIS) do not benefit from surgery, as researchers have long suspected.
Women with low-risk DCIS who were monitored with frequent mammograms were no more likely to progress to breast cancer over the next two years than women who had surgery to remove the abnormal cells, according to data presented on Thursday at the San Antonio Breast Cancer Symposium in Texas.
In DCIS – often called stage-zero breast cancer – abnormal cells are present inside the milk ducts, but they do not always evolve to become an invasive type of cancer.
In the U.S. alone, DCIS affects more than 50,000 women each year. Nearly all are treated with surgery, including many who undergo mastectomy.
The 957 women with DCIS in the trial were randomly assigned to undergo surgery or active monitoring. Most participants in both groups also received hormone-blocking therapy.
At two years, the rate of invasive cancer in the surgery group was 5.9%, compared to 4.2% in the active monitoring group, a difference that was not statistically significant, according to a report of the study published in JAMA.
“These early results are provocative and potentially exciting for patients, but we clearly need more long-term follow-up,” study leader Dr. E. Shelley Hwang of the Duke Cancer Institute in Durham, North Carolina said in a statement.
“If these results hold up over time, most patients who have this type of low-risk disease will have the option of avoiding invasive treatments. That would be a complete change in how we care for these patients and think about this disease.”
Ibrance extends control of type of breast cancer 15 months
Pfizer’s Ibrance helped keep metastatic breast cancer under control for significantly longer than usual in patients with a certain type of tumor, according to trial results presented on Thursday at the San Antonio meeting.
The nearly 500 patients all had advanced disease from so-called hormone receptor, or HR-positive, human epidermal growth factor receptor 2 – HER2-positive – tumors.
The median time to disease progression was 44.3 months with Ibrance on top of the usual treatments. Those who received only standard treatment went 29.1 months before the cancer began to worsen.
“These results support the potential of this maintenance treatment to slow disease progression and improve clinical outcomes in this patient population,” said Dr. Otto Metzger, an oncologist at the Dana-Farber Cancer Institute in Boston, who led the trial.
Approximately 10% of all breast cancers are HR- and HER2-positive. They are sometimes referred to as double-positive or triple-positive breast cancer. The tumor cells have surface proteins, or receptors, that bind to estrogen or progesterone, or both, as well as a surface receptor that binds to HER2, a protein that controls cell growth.
Ibrance was the first drug to act against the CDK4 and CDK6 enzymes, which play important roles in cell division, when it was approved in 2015.
More U.S. breast cancers being diagnosed at advanced stages
The number of women with late-stage, invasive breast cancer at the time of diagnosis increased significantly among U.S. women across all ages and ethnicities between 2004 and 2021, researchers reported on Tuesday in Radiology.
During that period, diagnoses of new breast cancer cases in which the disease had already spread in the body increased by an average of 1.16% per year, according to the report.
The biggest annual percentage increase in the incidence of metastatic breast cancer at diagnosis was 2.9%, seen in women between the ages of 20 and 39.
Among women aged 40–74 years, annual percentage increases were 2.1% from 2004 to 2012 and 2.7% from 2018–2021.
“It’s been previously reported that metastatic breast cancer at initial presentation has increased significantly for women under 40, but until now, no clear trend in older women has been reported,” study co-author Dr. Debra Monticciolo of the Foundation for Imaging Research and Education in Temple, Texas, said in a statement.
For women aged 75 years and older, the incidence rate increased by 1.4% over the study period.
The findings are drawn from the Surveillance, Epidemiology, and End Results database, which collected data on more than 71 million women each year.
Across ethnicities, Native American women had the largest annual percentage increase in rates of metastatic breast cancer at diagnosis, at 3.9%. The incidence in Asian women increased by 2.9% per year. Annual percentage changes among Black and Hispanic women were 0.86% and 1.6%, respectively.
Among white women, there was an annual percentage increase of 1.7% from 2004–2012, but no trend after that.
Incidence rates of metastatic breast cancers were 55% higher in Black women compared to white women, the researchers also reported.
“Fewer than 50% of U.S. women participate in annual breast cancer screening,” said Monticciolo, a past president of the American College of Radiology.
“That means we don’t have the opportunity to sweep out early-stage breast cancers in huge numbers of women, who will arrive at a later stage for diagnosis.”
(Reporting by Nancy Lapid; editing by Bill Berkrot)
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