Recent news headlines have suggested that women with the earliest form of breast cancer should rethink undergoing treatment because it may not impact their long-term survival. But breast cancer experts interviewed for this article say the study results that spurred those headlines should not be interpreted as a message to forego or change standard treatment.
In the observational study, available online ahead of print in JAMA Oncology (doi:10.1001/jamaoncol.2015.2510), scientists at the Women's College Research Institute in Toronto analyzed data from the National Cancer Institute's Surveillance, Epidemiology, and End Results database, which included information on 108,196 women with ductal carcinoma in situ (DCIS) who were followed for 20 years.
DCIS is the presence of abnormal cells inside a milk duct in the breast, the earliest form of breast cancer, sometimes called Stage 0. The lead study author, Steven A. Narod, MD, Senior Scientist and Director of the Familial Breast Cancer Research Unit, explained in an interview that DCIS is usually discovered during a mammogram, and that three standard treatment courses are typically available: lumpectomy, lumpectomy with radiation, or mastectomy. Sometimes medication is also prescribed. All the women in the study had received some type of treatment, he said.
Narod is also Professor in the Dalla Lana School of Public Health and the Department of Medicine at the University of Toronto, as well as a Tier 1 Canada Research Chair in Breast Cancer.
The study showed that women who undergo DCIS treatment have a 3.3 percent risk of dying of breast cancer after two decades—almost twice that by women in the general population.
“The three treatments seemed equivalent,” Narod said. “Most of the women who died of breast cancer had cancer that had spread by the time they were diagnosed with DCIS. The DCIS had probably already metastasized when it was diagnosed and local treatment wasn't sufficient.”
Jennifer Litton, MD, Associate Professor in the Department of Breast Medical Oncology at the University of Texas MD Anderson Cancer Center, said it's an interesting paper but that even more interesting has been the media coverage: “I think some people may have interpreted the paper based on their own bias or agenda. But when you read the paper, this was a very well-done, retrospective study using the SEER database of women with DCIS who received therapy and their outcomes. It does not tell us what happened to women with a diagnosis of DCIS who did not receive treatment.”
According to the American Cancer Society, 60,290 new cases of carcinoma in situ (CIS) will be diagnosed in the United States in 2015. The big debate raised in the recent news articles was: “Which, if any treatment should women with DCIS undergo to avoid recurrence?”
Litton, who was not involved with the study, clarifies: “The new study doesn't tell us at all that women with DCIS shouldn't get treatment.”
What it does offer, she said, is more a frame of reference. “This study does give us lovely background and insight into potentially who are the groups we should target for clinical trials in order to look at other methods of surveillance. But at this point, it in no way suggests that there should be a change to the standard of care in any practice.”
Litton said there's always been a lot of interest in looking at women who need less intervention, but that clinical trials to determine this approach are needed.
“Clinical trials are difficult to do, but before we can change the standard of care we're going to have to do that. This research is interesting and hypothesis-generating, but it isn't the information that tells us who we should and should not take to treatment.”
Don Dizon, MD, Clinical Co-director of Gynecologic Oncology at Massachusetts General Hospital Cancer Center, said, “The big message should not be lost: the vast majority of women diagnosed with DCIS survive.” Dizon was also not involved with the new study.
“DCIS is not a normal finding in the breast. So, finding something abnormal on histology prompts providers and patients for an action—what are we going to do about it? So much of decision-making is collaboration between those diagnosed and those who treat. I think it's wrong to suggest that doctors and surgeons are recommending treatment “aggressive” or “not so aggressive” in the absence of discussion,” Dizon told OT.
He said patients would bring their own goals and preferences to treatment: “What we need to do more of, or at least a better job of, is making sure that knowledge is imparted—inform the discussion through education of patients and their families, including making distinctions about in situ versus invasive breast cancer, and then informing our own treatments with the reasons why we do what we do.”
Dizon said that if anything, these data suggest that breast cancer specialists can be much more thoughtful in their approach to DCIS.
“It is not a one-size-fits-all approach. For example, we might recommend breast-conserving surgery and radiation therapy to younger women with DCIS. But maybe for older women over 65, we need only surgery to remove the lesion and not radiation.”
He said it's also important to look at DCIS as separate from invasive breast cancer – that these new long-term data show that women do well, better than can be expected, compared with women with invasive breast cancer.
Dizon also noted that because SEER data was used, “We do not know what treatment patterns, or even what the second cancers were, for those who developed invasive disease. Such data could inform the results, and we need to be cognizant of that.”
Laura Esserman, MD, MBA, Professor in the Departments of Surgery and Radiology and Director of the Carol Franc Buck Breast Care Center at the University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, wrote in an accompanying editorial that most of the women in the Narod et al study had lumpectomies and the rest had mastectomies. Some of the patients, she noted, were at higher risk, including younger patients under the age of 40, black women, and those with questionable molecular markers.
“The majority of DCIS is detected in women undergoing screening and who are recalled for biopsy of calcifications,” Esserman wrote. “To minimize the risk of overdiagnosis and/or overtreatment, it is time to reassess whether clustered amorphous calcifications should be a target for screening, recall, and biopsy, especially in older women.”
Esserman concluded by noting four points on what the sum total of the data on DCIS now suggests:
- DCIS should be considered a “risk factor” for invasive breast cancer and an opportunity for targeted prevention;
- Radiation therapy should not be routinely offered after lumpectomy for DCIS lesions that are not high risk;
- Low- and intermediate-grade DCIS does not need to be a target for screening or early detection; and
- Breast cancer specialists should continue to better understand the biological characteristics of the highest-risk DCIS cases and test targeted approaches to reduce death from breast cancer.
Deanna Attai, MD, President of the American Society of Breast Surgeons and Assistant Clinical Professor in the Department of Surgery at UCLA David Geffen School of Medicine, who also spoke with OT, said the study generated so much interest among colleagues and the broader breast cancer community that she addressed it on her blog (drattai.com/blog).
She told OT: “DCIS is not one disease. With each study that comes out, we get more and more evidence we're dealing with multiple diseases. Because we're dealing with multiple diseases, in a sense we need multiple treatment approaches—not a one-size-fits-all.
“Look at the patient's age, tumor grade, extent of disease, along with a patient's preferences and whether they understand these are our standard treatments but we're not sure about the long-term value of them in terms of improving survival. Couple that with understanding and recognizing that we don't have the ability to predict which patients will do well with less treatment.”
Attai, a co-moderator of the weekly Breast Cancer Social Media tweetchat (#BCSM), also said physicians need to have open discussions with their patients regarding the differences between DCIS subtypes, and that patients and doctors themselves need to recognize their limitations.
“We need to acknowledge that we do not always have the right answers, inform the patient that decisions do not need to be made quickly, discuss cases in a multidisciplinary forum, and encourage second opinions. I think that is the ideal way to approach a patient with DCIS—and invasive cancer, as well.”