Identifying Indolent vs Potentially Aggressive DCIS, More Research Needed

As part of our coverage for the ASCO Breast Cancer Symposium 2013, we spoke with Dr. Susan K. Boolbol, chief of the division of breast surgery at the Appel-Venet Comprehensive Breast Service at Beth Israel Medical Center in New York City. At the symposium, held September 7–9 in San Francisco, Dr. Boolbol is chairing a general session panel discussion on the overdiagnosis of breast cancer.

-Interviewed by Leah Lawrence

Cancer Network: Dr. Boolbol, why is the topic of overdiagnosis of breast cancer being featured as the welcome session at this year’s Breast Cancer Symposium? How large is the problem?

Dr. Boolbol: It is a very interesting topic that has really gained a lot of attention in the media. We felt that since ASCO is the leading cancer organization that this would be a good place to cover this topic and really agree or disagree with what is out there in the news today.

As far as how large a topic and problem this is, I think that we have to remember several things. Number one, this is a highly controversial topic within the medical world, within the cancer world, and within the world at large. This whole topic of overdiagnosis has been going on and been discussed for years, and remains very controversial.

It involves many different cancers but the topic today is breast cancer. The main issue with it is what we call ductal carcinoma in situ (DCIS), which is by definition a pre-invasive breast cancer. When we talk about how large a problem this is, pre-invasive breast cancer or ductal carcinoma in situ is a common diagnosis. The issue is-and this is where the controversial part comes in-is that we know that there are certain women with DCIS that left alone, it would never progress to become an invasive cancer. It would never cause them an issue in their life. There are others that can progress. The problem is that right now we do not have markers or any definitive way to differentiate the DCIS that could stay there and be an indolent disease and never cause that woman a problem from the DCIS that could potentially cause a problem.

So when we talk about the overdiagnosis, again a very controversial topic, we don’t know the numbers that are completely indolent and would never cause a problem compared with the ones that would cause a problem.

Cancer Network: A study published this year in the New England Journal of Medicine estimated that as many as 1.5 million women have been needlessly treated for breast cancers that may not have been harmful. What was the oncology community’s reaction to that estimate?

Dr. Boolbol: It was a very mixed reaction. Overall, people thought the number was incredibly high. Even the people who think that all DCIS is overtreated thought that number was high. But more than that-we have to be very careful with the term “needlessly treated” because for the women who don’t have their DCIS treated and they go on to develop invasive cancer, well it would not have been needless. Again, to date, we do not have a way to differentiate. There are many, many physicians in the oncology community that do not believe that we are overtreating this until we have markers-and that is really where we should be focusing our research, and there is a lot of research being performed in that area, but we really need more. That is where the key lies. Once we can differentiate between those DCIS cases that are indolent and will never create a problem from those that can potentially create a problem, we cannot continue to call it overdiagnosis. We need to be able to appropriately treat whatever we diagnose. That is really where we want the research focused.

Cancer Network: Three years ago, the US Preventive Services Task Force recommended against regular mammograms for asymptomatic women aged 40 to 49, and adjusted its recommendation for asymptomatic women aged 50 to 74 to every 2 years. How have these new recommendations affected breast cancer screening and diagnosis?

Dr. Boolbol: It is a very interesting question. It always takes several years to figure out the effect of a new policy or a new guideline, and those numbers are just starting to come out. Whenever we talk about screening, and even the numbers published for women who get mammograms, it always gives them a 2-year time period to get that mammogram. Now that we have 3 years past, we will start to see more in the medical literature regarding this topic. I can tell you at my hospital in New York City, we recently looked at our numbers and they have not decreased. That is because most people continue to follow the American Cancer Society’s guidelines, which is screening mammography at age 40. If you recall several years ago when the Task Force recommendations came out, there was enormous coverage of this in the media and enormous discussion of this in the medical world. Many people disagreed with and took issue with the studies that these recommendations were based on. I think some of it, if there is a difference in how many women are getting mammograms, it may be a geographical difference, but overall in the cancer community, we continue to follow the American Cancer Society guidelines.

Cancer Network: The Affordable Care Act will require that health plans cover preventive services such as mammograms. Is there any concern that this could add to the problem?

Dr. Boolbol: Point number one is that it is incredibly important that health plans cover not just mammograms but all preventive services. That is actually a fantastic thing about the Affordable Care Act. I think it is very important. We know that preventive services decrease certain cancers, certainly not all cancers, but certain cancers can decrease.

Is there a concern that this could add to the problem? By shear virtue of a screening test, the more we do, the more we will find, so the more women that get mammograms, it is a fixed percentage that we will find abnormalities that require biopsies and potentially further work-up.

One of the things we have to remember is that as technology improves, specifically as imaging technology improves, we will find more abnormalities on these images, specifically on mammograms. It is up to the researchers in the medical community to help solve these problems as to which abnormalities do we have to treat and which can we leave alone. That is really where the answer is going to lie. It is going to lie in the research being done.

Cancer Network: What sort of policies can be put in place to prevent or reduce the overdiagnosis and treatment of breast cancer?

Dr. Boolbol: I don’t think that this is a policy issue. I really don’t. I think that what we need to get to is healthy, informative, educated discussions between the physicians and the patients. That really is the key on both sides. The physicians have to be willing to have these discussions. The patients have to be willing to be a participant in their health care.

For instance, when a woman is diagnosed with DCIS, a discussion has to be had that says chances are that this will not affect your overall health, but I cannot say that with 100% certainty. We can have these educated discussions with our patients, and ultimately it comes down to making the decision together. They really do need to be a participant in these decisions. Ultimately, what we get to is personalized medicine. If we diagnose a 95-year-old woman with ductal carcinoma in situ, should we be treating her the same as a 40-year-old woman? It is not just based on age alone, it is based on the intentions of the patient. It is based on their overall health. It is based on so many factors, and that is why these discussions are so important.

As opposed to setting policies, we tend, in the medical world, to set guidelines, and that allows for these discussions and tailored medical care to the individual patient.

Cancer Network: What is the most important take-away message on breast cancer overdiagnosis for oncologists who are not able to attend the symposium?

Dr. Boolbol: Number one is that this remains a very controversial issue. Not all physicians in the cancer world agree on the term “overdiagnosis” or even what it means. The major take-away message is that we need more research in this area. Until we have a way or a definitive test or definitive markers to determine which DCIS is indolent and will not create any sort of problem and which DCIS will go on to potentially create a problem, it is difficult to differentiate who we treat and who we do not treat.

And that is why the discussion between the physician and the patient is so important. We need more research into this area.

Cancer Network: Okay, great. Well, thank you again for taking the time to speak with us today.