(HealthDay News) – For older women with invasive breast cancer, treatment with brachytherapy following a lumpectomy is associated with a decreased likelihood of long-term breast preservation and an increased likelihood of complications, but no difference in overall survival, compared to whole-breast irradiation (WBI) treatment.

Grace L. Smith, MD, PhD, MPH, from the University of Texas MD Anderson Cancer Center in Houston, and colleagues retrospectively analyzed data from 92,735 women (aged ≥67 years) with incident invasive breast cancer, diagnosed between 2003–2007 and followed up through 2008. Patients were treated with brachytherapy (6,952 women) or WBI (85,783 women) following lumpectomy.

The researchers found that the five-year incidence of subsequent mastectomy was significantly higher in women treated with brachytherapy compared to WBI (3.95 vs. 2.18%), and this association persisted after adjusting for other variables. Brachytherapy was associated with significantly more frequent infectious and noninfectious postoperative complications (adjusted odds ratio, 1.76 and 2.03, respectively). Brachytherapy also correlated with significantly higher five-year incidence of breast pain, fat necrosis, and rib fracture. Differences in five-year overall survival were nonsignificant for patients treated with brachytherapy versus WBI (87.66 and 87.04%, respectively; adjusted hazard ratio, 0.94; P=0.26).

“Potential public health implications of these findings are substantial, given the high incidence of breast cancer, along with the recent rapid increase in breast brachytherapy use,” the authors conclude. “Although these results await validation in the prospective setting, they also prompt caution over widespread application of breast brachytherapy outside the study setting.”

One author disclosed a financial relationship with Varian Medical Systems.

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