Persistent Use of Extended Fractionation Palliative Radiation Therapy for Medicare Beneficiaries with Metastatic Breast Cancer: 2011-2014

Abstract

In response to the lack of evidence supporting extended radiotherapy fractionation for the palliative treatment of bone metastases, multiple guidelines were issued from 2011-2013 discouraging its use. We assessed contemporary use and cost implications of prolonged treatment course in a sample of Medicare beneficiaries with breast cancer who received palliative radiotherapy for bone metastases. We conducted a retrospective, longitudinal study of palliative radiotherapy use among fee for service Medicare beneficiaries, using the Chronic Condition Warehouse (CCW) database. We used ICD-9 diagnosis and procedure codes to identify women with breast cancer bone metastasis who underwent palliative radiotherapy during 2011-2014. Patients were then categorized according to the number of days (‘fractions’) on which they received palliative radiotherapy: 1, 2-10, 11-19, or 20-30. We analyzed the association between patient clinical and demographic characteristics, provider characteristics, and the use of extended fractionation (defined as 11 or more fractions). We compared treatment cost associated with the different fractionation schemes. All costs were inflation adjusted to 201x U.S. dollars. Of the 7,547 patients in the sample (mean age 71 years), 3,084 (41%) received at least 11 fractions. The proportion of patients receiving 11-19 (34.7% in 2011 and 28.1% in 2014) and 20-30 treatments (10.3% in 2011 to 9.0% in 2014) decreased modestly over time, but remained persistently high. Patients with more comorbidities (>2 comorbidities vs. 0 comorbidities) were less likely to undergo extended fractionation (adjusted odds ratio [AOR] 0.67 [95%CI 0.58-0.76]). Patients treated at freestanding practices were more likely to undergo extended fractionation compared to those treated at hospital-based practices (70.0% vs. 30.0%, p<.001; AOR 1.42 [95% CI 1.27-1.60]). The mean cost of treatment varied from $6,597 [Standard deviation (SD) $2,893] for 20-30 fractions, to $3,566 [SD $1,349] for 11-19 fractions, and $633 [SD $240] for single fraction treatment. The use of prolonged course palliative radiotherapy among Medicare beneficiaries with breast cancer remained persistently high in 2011-2014, despite lack of evidence for its clinical benefit and higher costs in comparison to shorter course treatment. The association between freestanding facility status and use of extended fractionation suggests that provider financial incentives may impact choice of treatment.