The best way to treat — or not to treat — a possible precursor to breast cancer has women considering their options while experts offer conflicting advice. A new review published in the journal JAMA Oncology stresses that the best care is to actively treat ductal carcinoma in situ, also known as DCIS.
DCIS occurs when abnormal cells are confined to the milk ducts in the breast. Often called “pre-cancer” or “stage zero” cancer, the most accurate term is simply DCIS, said Cleveland Clinic radiation oncologist Dr. Chirag Shah.
“Pre-cancer is a misleading term. Stage zero can refer to other things such as LCIS (lobular carcinoma in situ). It’s best to simply call it DCIS,” he said.
50/50 chance
If a woman is diagnosed with DCIS, she is at higher risk for developing an invasive form of cancer, Shah said.
“Without treatment we know that 50 percent of the time, roughly, these cancers can become invasive cancers so that’s the reason that we do treat them aggressively and don’t just observe them,” he said. “Of the people who are treated for DCIS who later develop cancer, half of those occurrences are invasive cancers.”
Diagnosis of DCIS has soared in recent decades because of an increase in mammography screenings, Shah said. Radiologists with better tools are now able to find smaller lesions and are paying attention to smaller amounts of calcifications.
While more women are being diagnosed with DCIS, there’s not a lot of data available for researchers to review because most people with DCIS have been treated rather than untreated, Shah said.
Shah and his team reviewed 50 studies to determine the best course of treatment for DCIS: a conservative wait-and-see approach or the standard regimen of surgery, radiation and endocrine therapy.
After summarizing the data, the group found that actively treating DCIS with the standard regimen is still the best option for most people. According to the review, data show that radiation after surgery can reduce the risk of cancer recurring in the breast.
“The results of our review demonstrated at this time DCIS is best managed using traditional treatments, so surgery, followed by radiation in appropriately selected women,” said Shah.
Research ongoing
Not all DCIS becomes invasive cancer, and that leads some people to doubt the value of undergoing surgery. For women who choose a more conservative approach, Shah suggests they do so “under the guidance of a clinical trial.”
To find a trial near you that matches your diagnosis, visit the clinical trials page on the National Cancer Institute’s website, cancer.gov/about- cancer/treatment/clinical-trials/search.
The area of DCIS continues to evolve and research is ongoing, Shah said. For now, it’s important for women diagnosed with DCIS to talk to their doctor about the benefits and risks of each treatment option.