WASHINGTON, DC — Digital mammography and magnetic resonance imaging (MRI) are ushering in a new era in the detection of ductal carcinoma in situ (DCIS) in the United States, according to experts here at the Society of Surgical Oncology 66th Annual Cancer Symposium.
Advanced technologies in breast cancer screening — and their enhanced imaging — increase the detection of abnormal cells in the breast, said E. Shelley Hwang, MD, from Duke University in Durham, North Carolina.
However, this improvement in technology outpaces oncologists' knowledge of what to do about the abnormalities, she told Medscape Medical News.
In the United States, these abnormalities are regularly called DCIS and are invariably treated with some combination of surgery, radiation, and systemic therapy, Dr. Hwang explained. This means a lot of overtreatment, because 60% to 80% of DCIS is benign and will never progress to an invasive cancer, she said during a debate on how to handle DCIS in the clinic.
In the 1980s, before the advent of widespread mammography screening, about 1% of all breast cancers were considered DCIS, said Seema Khan, MD, from Northwestern University in Chicago, Illinois. She moderated the debate between Dr. Hwang and Thomas Julian, MD, from Drexel University in Philadelphia, Pennsylvania.
Dr. Khan showed a graph depicting the incidence of DCIS from 1975 to 2005. The DCIS line on the graph climbs steadily, and the rate will continue to rise, said Dr. Khan. "We haven't really seen the end of this trend yet," she told the audience.
Currently, there is a predicted "bump in the harvest of DCIS with the use of digital mammography and MRI," she said.
Dr. Julian agrees. In 2009, 25% of all breast cancers diagnosed in the United States were considered DCIS, and there were 54,000 cases of DCIS in 2010.
However, the number of DCIS cases is "ramping up" because of digital mammography and MRI, said Dr. Julian. It has been proven that MRI picks up more DCIS, both low and high grade, than standard mammography.
Another new technology could push DCIS detection even higher, noted Dr. Julian. "Who knows what will happen when we get to 3D tomosynthesis mammography, [and who knows] how much more we will be detecting," he said.
With the market adoption of more powerful imaging and the rising rate of DCIS, "this will be a continuing problem," said Dr. Julian.
What to Do in the Clinic?
The "big challenge" of DCIS is "distinguishing the lesions that will and the lesions that won't" progress to invasive cancer, said Dr. Khan. Improvement in stratification could lead to less standard treatment of the condition, she noted.
Dr. Julian described this stratification as the need to "separate out the good, bad, and ugly of DCIS."
However, Dr. Julian does not put much stock in the available methods for stratifying DCIS, including genetic assays that predict the likelihood of recurrence, and argued for standard treatment of all DCIS cases.
Such an approach results in significant overtreatment of DCIS, noted Dr. Hwang.
She and Dr. Khan argued for observing some patients with DCIS, with or without surgery. The "DCIS end point that we all worry about is invasive cancer," Dr. Khan told Medscape Medical News. But in DCIS patients, invasive cancers are "almost always treatable," she said.
"The death rates in all of the DCIS trials are extremely low because the invasive cancers that happen are successfully treated," she said. Therefore, clinicians could "start treatment once invasive cancer shows up," Dr. Khan pointed out.
Dr. Hwang encouraged clinicians to use decision aids with DCIS patients to help make treatment decisions. Also, pay attention to your language; it can deeply influence your patients' thinking, she explained.
Dr. Hwang and colleagues proved this point in a survey of almost 400 DCIS patients with hormone-receptor-positive disease.
The unique element in the survey was that 3 different terms were used to describe the DCIS; participants were informed that they had "noninvasive breast cancer," "abnormal cells," or a "lesion."
The women were then presented with 3 clinical options — surgery, medication, or active surveillance (observation) — and some information on outcomes.
Table. Outcome Information Provided to Women Diagnosed With DCIS
|Chance of developing invasive breast cancer in next 10 years||3.0%||17.0%||30.0%|
|Chance of dying from breast cancer in next 10 years||0.3%||1.7%||3.0%|
Dr. Hwang reported that the words describing the condition deeply influenced the patient's choice of treatment. For example, if it was called a noninvasive cancer, 47% of the women chose to undergo surgery; however, if was called either a lesion or abnormal cells, then only about one third of the women chose surgery.
"Cancers are a bounded set that can invade and metastasize. DCIS is not a cancer," said William Wood, MD, from Emory University in Atlanta, Georgia, who was not part of the debate but spoke up during the discussion period. He also pointed out that "prediabetes" is not diabetes.
A change in DCIS nomenclature would bring breast disease into alignment with other conditions, Dr. Khan explained.
Ductal intraepithelial neoplasia was accepted as an alternative to DCIS in 2003 by the World Health Organization, she noted. The term "intraepithelial neoplasia" is already used with many other organs, including the cervix, vagina, prostate, pancreas, and colorectum. Why not include the breast?, Dr. Khan asked.
Dr. Hwang reports financial ties with Genomic Health and Merck. Dr. Julian and Dr. Khan have disclosed no relevant financial relationships.
Society of Surgical Oncology (SSO) 66th Annual Cancer Symposium. Presented March 9, 2013.
Medscape Medical News © 2013 WebMD, LLC
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Cite this: In US, Even More DCIS Is Coming: What Should Be Done? - Medscape - Mar 12, 2013.