Oncologists Skeptical of Omitting Radiation Therapy in Early-Stage Breast Cancer in Older Women

Should older women with stage I estrogen receptor (ER)—positive breast cancer receive radiation therapy? While clinical trials have shown that 90% of older women (older than 70 years) with breast cancer do not benefit from radiation following breast-conservation surgery, the use of radiation treatment has not dropped significantly in this sub-population of patients. Following a national survey, researchers at the University of Michigan now understand why this is so.

The authors of the study, which has been published in the Annals of Surgical Oncology, surveyed a national sample of 713 radiation oncologists and 879 surgeons—about 825 of the eligible 1504 physicians (55%) responded to the survey. Survey questions delved into clinical scenarios, knowledge of pertinent risk information, and correlates of views on radiotherapy omission.

About 40% of surgeons and 20% of radiation oncologists felt that omitting radiotherapy in patients older than 70 years who had stage I, ER-positive breast cancer, who had received lumpectomy and endocrine therapy, was unreasonable. Interestingly, the authors found that 29% of surgeons and 10% of oncologists who were surveyed “erroneously associated radiotherapy in older women with improvement in survival.”

A downstream effect of this belief was that 32% of surgeons and 19% of radiation oncologists overestimated the risk of locoregional recurrence in older women who had not received radiation therapy. Even in patients who presented with multiple comorbidities, the physicians did not hold back on radiotherapy, the study found.

Addressing the availability of recent evidence that points to favorable outcomes in this patient population, even in the absence of radiotherapy, the study first author, Dean Shumway, MD, said in a statement.

“Radiation does not appear to prolong survival," he said. "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%.”

Shumway highlighted that an unexpected finding of their study was that surgeons were more uncomfortable with omitting radiotherapy than were radiation oncologists.

Based on the survey results, the authors conclude that many radiation oncologists and surgeons strongly consider omitting radiotherapy as substandard treatment. However, they believe that a change in this attitude could avoid overuse of aggressive care in this particular clinical setting.

“Our study provides a detailed view into the physician perspective on how the decision is made to omit radiotherapy. We hope this insight will be useful in improving delivery of individualized care for older women with early stage breast cancer,” Shumway added.

Reference

Shumway DA, Griffith KA, Sabel MS, et al. Surgeon and radiation oncologist views on omission of adjuvant radiotherapy for older women with early-stage breast cancer [published online July 26, 2017]. Ann Surg Oncol. doi: 10.1245/s10434-017-6013-1.