The use of adjuvant radiotherapy in elderly women with early-stage breast cancer has declined since the publication of study results showing that lumpectomy and tamoxifen therapy were preferable to radiotherapy in this patient group, but nearly two-thirds of these women continue to receive adjuvant radiotherapy, according to analysis of data from the Surveillance, Epidemiology, and End Results registry.

SEER data from 40,583 women showed that, between 2000 and 2004, 68.6% of eligible patients –women aged over 70 years with stage 1, estrogen receptor–positive breast cancer – received adjuvant radiotherapy, but this declined to 61.7% of patients between 2005 and 2009, representing a small but statistically significant decline.

Radiotherapy use declined significantly across all age groups, tumor sizes, and grades, regardless of laterality, although it was used slightly less frequently in patients aged over 85, compared with those aged 70-74 years, according to a study published online Dec. 8 (Cancer 2014 [doi:10.1002/cncr.28937].

“Data supporting the omission of radiotherapy in elderly patients has emerged simultaneously with promising long-term results from partial breast irradiation trials and data demonstrating the equal efficacy of conventionally fractionated whole-breast radiotherapy compared with more hypofractionated whole-breast regimens,” wrote Dr. Manisha Palta of Duke University, Durham, N.C., and her colleagues.

“These data may partially explain why older women continue to be offered and receive adjuvant radiotherapy,” they said.

Additional reasons why data from randomized trials may not be incorporated into clinical practice could include financial incentives and the fact that “the medical community may react differently to withholding treatment compared with adding a new treatment,” Dr. Palta and her colleagues said.

There were no conflicts of interest declared.