Radiation of Limited Benefit in Older Women With Early Breast Cancer

Women older than 70 years of age who have certain early stage breast cancers overwhelmingly receive radiation therapy despite published evidence that the treatment has limited benefit.

A recent study suggests that doctors and patients may find it difficult to withhold treatment previously considered to be the standard of care, even in the setting of high-quality data demonstrating that the advantages are small, researchers at Duke Medicine report.

“The onus is on physicians to critically analyze data to shape our treatment recommendations for patients, weighing the potential toxicities of treatment against clinical benefit,” says Rachel Blitzblau, MD, PhD, who is the Butler Harris Assistant Professor of Radiation Oncology at Duke University Medical Center. Blitzblau was the senior author of a study published online Dec. 8, 2014, in the journal Cancer.

Blitzblau and colleagues launched their inquiry to determine whether clinical practice changed as a result of a large randomized, prospective study first published in 2004 that compared treatment options for women ages 70 and older with early stage hormone receptor–positive breast cancers. The CALGB 9343 study reported limited benefit among older women for adding radiation therapy plus tamoxifen after lumpectomy.

Specifically, the 2004 study’s 5-year data showed a small but statistically significant reduction in the rate of cancer recurrence; a similar finding was reported again in 2012 with a decade of data. However, the addition of radiation to tamoxifen after surgery did not improve overall survival among the study participants during either of the reporting periods.

“The discussion at the time of the first CALGB report in 2004 was that we should consider omitting radiation for these women, because the small observed benefits might not be worth the side effects and costs,” Blitzblau says, adding that side effects include fatigue, discomfort, and changes in the radiated breast tissue, among other issues.

But little has changed following publication of the study, with about two-thirds of women still getting radiation therapy. Blitzblau and colleagues analyzed cancer treatment patterns from a national health database called the Surveillance, Epidemiology, and End Results (SEER) registry. They found that before the CALGB study results were published in 2004, 68.6% of older women who would have been eligible for enrollment in the CALGB trial received radiation therapy. In the 5 years after the study was first reported, the rate dropped, but only slightly, to 61.7%.

“The publication of the trial had only a very small impact on practice patterns,” Blitzblau says. “Our findings demonstrate the potential difficulty of incorporating clinical trial data that involves omitting a treatment that has been considered the standard of care.”

She says physicians might have delayed making practice changes until longer-term data were available; the research team’s analysis did not include results after the 10-year data from CALGB were published in 2012. In addition, she says, there is likely lingering concern among both doctors and patients that reducing treatments may worsen outcomes for older women who have excellent overall health and therefore longer life expectancies.

But Blitzblau says the findings of the current study highlight an important and increasingly difficult challenge for physicians: striking the right balance between offering effective treatments while also acknowledging the need for more financially efficient medical care.

“It’s important to improve patient and doctor communication to ensure that the right patients are getting the right treatment at the right time,” Blitzblau says. “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.”