Interview conducted by April Cashin-Garbutt, BA Hons (Cantab) on 14th August 2012
Please could you give us a brief introduction to early stage breast cancer in older women?
Early stage breast cancer in older women is a common problem. In the United States nearly half of women diagnosed with breast cancer are aged 65 or older. A sizeable proportion of those patients have early stage breast cancer.
Early stage breast cancer is stage 1 breast cancer. This is where the tumor is 2cm or less in size and has not spread to lymph nodes.
How frequently do older women with breast cancer require mastectomy?
For early stage breast cancer there are three general treatment options. One option is to do a lumpectomy; and just take endocrine therapy, which is a pill which blocks estrogen in the body.
Another option is a lumpectomy followed by radiation treatment to the breast, also with endocrine therapy.
The third option is to do a mastectomy. This does not require any radiation treatment.
What are the current clinical recommendations regarding radiation after lumpectomy?
In the US one of the key bodies that helps to provide us with recommendations is the National Comprehensive Cancer Network. They have a guideline statement that indicates that for older women, aged 70 or older, with stage 1 breast cancer that is estrogen-receptor positive, meaning that it is a hormone sensitive tumor, that radiation therapy can be omitted. Instead patients can just take endocrine therapy.
How did your research originate?
The topic of the role of radiation in older women has been of interest to me for quite a few years. I published a paper on this topic back in 2006. Recently, I’ve been interested in updating some of our studies on this topic.
One of the things that made me particularly interested in this topic was when the guidelines were changed back in 2005. This was when they said that women in this group don’t need radiation. In my own practice, I began offering no radiation to my patients.
The first patient that I offered no radiation to chose not to receive radiation. Then two years later her cancer came back and she had a mastectomy.
The second patient that I offered no radiation to came back to my practice 3 weeks later because she couldn’t tolerate endocrine therapy, so she wanted to do radiation instead. She did great with radiation.
In my personal practice as a physician trying to implement this guideline, I ran into unforeseen events. This made me interested in looking into this question with a large data set.
What did your research find?
We found about 7000 women who would meet this definition for early stage breast cancer that was estrogen-receptor positive. All these patients were between ages 70 and 79.
We found that in this population, women who received radiation had a lower risk of having a mastectomy in their follow-up period.
The mastectomy would really be indicating that their cancer had come back in the breast and they were receiving surgery to remove the breast to treat the recurrence of cancer.
Is radiation after lumpectomy beneficial for all older women or only some?
What was particularly helpful about our study was that we identified some women who did not really benefit from radiation therapy at all. This was consistent with the guidelines that say that radiation was not needed.
The women who did not benefit were women who were aged 75 and older who did not have aggressive-looking tumors when you look at them under a microscope.
In contrast, we found that patients, regardless of their age, who had an aggressive-looing tumor (when you look under the microscope) all seemed to benefit much more from radiation than you would have guessed based on the guideline statement.
What impact will your research have on national guidelines?
That is a good question. One of our co-authors on this paper is a representative from the National Comprehensive Cancer Network Breast Cancer guideline committee; so I think it may provide some more material for discussion the next time this group convenes to discuss the guidelines.
I think it will probably add a layer of complexity and controversy to the guideline statements. There’ll probably be differing opinions on how much the data should impact these guidelines.
What factors should patients take into account when deciding whether or not to undergo radiation?
There are several factors that are worth paying attention to. What we found specifically in our study was that patients who had aggressive tumors when you look under the microscope, these are called high grade tumors, seem to benefit much more from radiation. So clearly the grade of the tumor is important.
Other factors that we couldn’t look at in our study, but that are probably important, are the margin status. If the surgeon takes a very large rim of normal tissue out when he/she removes the tumor, then this is probably more reassuring that the patient does not need radiation.
In contrast, if the surgeon cuts very close to the tumor, some tumor cells could still be left behind. This is a reason why you may be more in favor of radiation treatment.
The other thing that older women particularly need to take into account with their physicians is their expected life expectancy. If they have a lot of other medical problems and may pass away in a few years from other problems, they probably don’t need radiation. Radiation is more about giving a long-term benefit in lowering recurrence over the next 10 years.
Ideally, the patients we should be treating are those for whom we expect a good ten year survival rate.
How do you think the future of treating breast cancer in older women will develop?
There are several different lines of investigation. One line is trying to understand in a more sophisticated way on a molecular level what are the molecular characteristics of the tumor that drive the risk for recurrence, so that we can make decisions for our patients more based on the molecular profile of the tumor rather than some of the crude things we use right now, like age and grade. So, it is possible over time that we may develop molecular tests that may be more specific at determining who may need radiation therapy.
The other move in radiation has been to make radiation more convenient for patients. For many years, the standard treatment in the United States has been to give about 6 weeks of daily radiation treatment - so about 30 treatments in total. This is very inconvenient for patients.
The investigators in the UK have been pioneers and leaders in trying to shorten the course of radiation treatment. They’ve demonstrated, through a series of very well-done scientific studies, that the treatment course for radiation therapy can be abbreviated to as few as 15 treatments without compromising either the safety or the effectiveness of radiation treatment.
This is used more commonly in the UK. In the US, we tend still to use longer schedules; but I think the future is moving towards more convenient treatments for our patients.
Please can you tell us a little bit about internal radiation therapy?
There is still a lot of controversy and differing opinions regarding internal radiation therapy. There is an article from the UK called the Targit trial, where they showed that one internal radiation treatment given at the time of lumpectomy was just as good as more standard treatments.
That trial has relatively short follow-up, though, and it appears that many patients were lost to follow up. So, at least some people want to see more long-term, complete, follow-up data on that trial before necessarily adopting it universally in their practice.
I think it is an interesting trial and it may be important in changing the way we think about treating breast cancer.
What are your plans for further research into this field?
Almost at the same time we published a second paper, published in the Journal of Clinical Oncology, where we developed a nomogram, which is a risk-prediction tool, for all older women with breast cancer treated with lumpectomy to help predict the risk of mastectomy and the benefit of radiation.
That was our follow-up project and it just so happens that both projects were published at the same time.
We’re working to make this nomogram publicly available on the MD Anderson website, so any patient or physician could come and very easily put in a few characteristics about their tumor and their treatment and get an idea of what their risks of mastectomy would be, with or without radiation treatment. This would help them to make more personalized decisions.
Where can readers find more information?
They can find more information on the nomogram here: http://jco.ascopubs.org/content/30/23/2837.long
About Dr. Benjamin Smith
Dr. Smith is Assistant Professor of Radiation Oncology at The University of Texas MD Anderson Cancer Center. He received a B.S. in biochemistry from Rice University, summa cum laude, and his M.D. from Yale University, cum laude.
Dr. Smith specializes in breast cancer radiation oncology and maintains an active portfolio of health services research projects. He is also the vice-chair of the ASTRO (American Society for Radiation Oncology) Guidelines Subcommittee and was lead author of two major guidelines on breast cancer radiation therapy on behalf of ASTRO.
He serves as the principal investigator for an MD Anderson Cancer Center Trial which compares two different schedules of whole breast irradiation. This trial is funded by a Career Development Award granted to Dr. Smith from the Conquer Cancer Foundation on behalf of the American Society for Clinical Oncology (ASCO).
Prior to joining MD Anderson, Dr. Smith completed his internship and residency at Yale-New Haven Hospital where he was Chief Resident and received a Young Investigator Award from ASCO.
Upon completing residency, Dr. Smith served in the United States Air Force Medical Corps, reaching the rank of Major. He was also Chief Radiation Oncologist at Wilford Hall Medical Center in San Antonio, Texas. He received the Meritorious Service Medal from the US Air Force in 2010.
He has authored or co-authored over 40 peer-reviewed research articles, 15 textbook chapters, and over 30 invited articles or editorials. His research interests include using population-based data, from sources such as Medicare claims, SEER-Medicare, SEER, and the Texas Cancer Registry, to elucidate cancer care patterns, quality, outcomes, and complications.
His work has been featured in numerous journals including JAMA, Journal of Clinical Oncology, Journal of the National Cancer Institute, Cancer, and the International Journal of Radiation Oncology, Biology, and Physics.
His research has also been featured in numerous media outlets including ABC News with Diane Sawyer, National Public Radio, The New York Times, and The Wall Street Journal.
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