Paul Basilio, MDLinx | October 11, 2017
Results of recent trials have suggested that the majority of patients older than 70 years of age with early-stage breast cancer do not benefit from radiation after breast-conserving surgery,1,2 but the subsequent drop in radiation in this patient group has not been as significant as was expected. A team of researchers at the University of Michigan believe they know why, and have published their findings in The Annals of Surgical Oncology.
“In the last 30 to 40 years, we’ve learned the value of doing less,” says study author Dean Shumway, MD, Assistant Professor of Radiation Oncology at Michigan Medicine. “In breast cancer, we’ve gone from radical mastectomy with removal of the breast and pectoralis muscle, to a modified radical mastectomy with removal of the breast, to breast conservation and radiation without negatively affecting outcomes.”
Researchers are now beginning to identify whether patients who undergo lumpectomy can take a pass on radiation without a negative effect on outcomes. Two recent prospective clinical trials, for example, observed a favorable outcome among older women with stage 1, estrogen receptor-positive breast cancer, even with omission of radiotherapy.1,2
“These studies showed that whether or not older women with small tumors receive radiation, they live the same amount of time,” Dr. Shumway said. “Radiation does not appear to prolong survival. Even though it does significantly decrease the chance of the tumor coming back, after 10 years it was only a 10% recurrence rate without radiation. With radiation, it would reduce the recurrence rate to about 2%.”
In other words, he said 90% of these patients would do well with a lumpectomy alone and would not benefit from radiation, as long as they are compliant with endocrine therapy for five years.
Still, these findings have not significantly changed the way physicians treat this subset of patients.
“There was some change, mainly in the oldest and sickest patients, but 60% of patients older than age 80 still receive radiation,” Dr. Shumway explained. “My goal with this study was to investigate how physicians view the option of omitting radiotherapy, with the goal of understanding more about why practice patterns haven’t changed. Until now, no one had asked them.”
The team of researchers at U-M conducted a postal survey of 879 surgeons and 713 radiation oncologists who regularly treat patients with breast cancer. The questions were designed to evaluate physician attitudes, knowledge, communication, and recommendations regarding the omission of radiation therapy in older women with early-stage breast cancer.
Results showed 40% of surgeons and 20% of radiation oncologists were uncomfortable with omitting radiation following lumpectomy. A sizable minority of respondents in both specialties erroneously associated radiotherapy in this scenario with improvement in survival for patients with early-stage cancer. They also overestimated the risk of local recurrence if radiation is omitted.
In addition, clinicians who overestimated the benefits of radiotherapy were more likely to consider radiotherapy omission to be an unreasonable option.
To better assess attitudes, the survey proposed specific patient scenarios. In one scenario, physicians were asked if they would recommend radiation to an unhealthy 81-year-old woman who was a borderline surgical candidate.
One-third of the respondents said they would—a margin that surprised the research team.
“The finding that we didn’t expect was that surgeons are generally more uncomfortable with the idea of omitting radiation than radiation oncologists are,” Dr. Shumway said. “It’s viewed as a departure from the standard of care.”
A majority of physicians who were surveyed reported that patients want the most aggressive treatment, even if the benefit is small. It can take more effort to tell patients that they do not need radiation than it does to recommend it.
“It’s important to recognize that this is a controversial area,” Dr. Shumway explained. “You can’t say that offering radiation to older women is wrong. It really is a patient-driven decision and it depends on the patient’s own values and preferences, in addition to her risk of recurrence and overall health.”
As the point of first contact for breast cancer patients, surgeons have a significant influence on how patients choose treatment options, which is why Dr. Shumway thinks they could play a crucial role in counseling older women about options for less aggressive therapy.
“The population is aging, and this is going to be an issue that affects more women,” he said. “There is increasing attention given to considerations that are unique to older patients — and in this case, their vulnerability for overtreatment.”
Dr. Shumway’s future work will focus on developing interventions to help patients make fully informed decisions and understand the concept of competing causes of mortality.
This study was supported by a grant from the Conquer Cancer Foundation, the Breast Cancer Research Foundation, and intramural pilot project funding from the Cancer Surveillance and Outcomes Research Team (CanSORT), and by the National Cancer Institute of the National Institutes of Health.
To read more about the study, click here.
1. Hughes KS, et al. J Clin Oncol. 2013 Jul 1;31(19):2382-7.