Breast Cancer: Older Patients Still Receiving Radiation Therapy Despite Limited Benefit

Rachel Blitzblau, M.D., Ph.D. Butler Harris Assistant Professor Department of Radiation Oncology Duke University Medical Center Durham, NC Interview with:
Rachel Blitzblau, M.D., Ph.D.

Butler Harris Assistant Professor
Department of Radiation Oncology
Duke University Medical Center
Durham, NC 27710

Medical Research: What is the background for this study? What are the main findings?

Dr. Blitzblau: Radiation reduces the risk of loco-regional recurrence. Data from the CALGB 9343 study suggests that the local benefit from adjuvant radiation is less in older women with small, estrogen receptor positive breast cancers. The potential acute and late toxicities of radiotherapy, patient inconvenience and healthcare costs must be considered given the small clinical benefit associated with adjuvant radiotherapy in this patient group. We looked at rates of radiotherapy in women fitting the entry criteria of this trial before and after publication of 5 year results of the CALGB trial. We found an approximately 5% decrease in use of radiotherapy overall, and noted that there seemed to be a small but significant shift in the type of radiotherapy used for these patients. Less patients received standard whole breast radiotherapy, and more received a short course of treatment to just the tumor bed plus margin called accelerated partial breast irradiation. We concluded that the publication of the trial therefore had only a very small impact on practice patterns.

Medical Research: What should clinicians and patients take away from your report?

Dr. Blitzblau: Understanding practice patterns is an important first step to improving patient care. Are most Radiation Oncologists practicing in an evidence based way? Are there barriers to acceptance or adoption of new clinical trial data? Given the results of the CALGB 9343 study, omission of radiotherapy in women over age 70 with small, estrogen receptor positive tumors who take adjuvant hormonal therapy should be considered and discussed with patients. However, it is important to also incorporate other clinical factors, such as medical comorbidities, life expectancy, and pathologic tumor features, as well as patient’s preferences into treatment recommendations.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Blitzblau: It will be interesting to see if the 10 year data, published in 2012, after the years available in the database for our study, had a larger impact on practice patterns. That would suggest that practitioners needed to see longer term outcomes to feel comfortable omitting a treatment previously considered standard of care. If there is still no change after that, then the question will be why. As we work toward more efficient and evidence-based medical practice in all medical specialties, we will need to understand what processes may be needed to spur change. Future research should focus on what the barriers may be to incorporating new data into practice, and what might help physicians and patients feel comfortable with that.