Uptake and costs of hypofractionated vs conventional whole breast irradiation after breast conserving surgery in the United States, 2008-2013

Abstract

Importance: Based on randomized evidence, expert guidelines in 2011 endorsed shorter, hypofractionated whole breast irradiation (WBI) for selected patients with early-stage breast cancer and permitted hypofractionated WBI for other patients.

Objectives: To examine the uptake and costs of hypofractionated WBI among commercially insured patients in the United States.

Design, setting, and participants: Retrospective, observational cohort study, using administrative claims data from 14 commercial health care plans covering 7.4% of US adult women in 2013, we classified patients with incident early-stage breast cancer treated with lumpectomy and WBI from 2008 and 2013 into 2 cohorts: (1) the hypofractionation-endorsed cohort (n = 8924) included patients aged 50 years or older without prior chemotherapy or axillary lymph node involvement and (2) the hypofractionation-permitted cohort (n = 6719) included patients younger than 50 years or those with prior chemotherapy or axillary lymph node involvement.

Exposures: Hypofractionated WBI (3-5 weeks of treatment) vs conventional WBI (5-7 weeks of treatment).

Main outcomes and measures: Use of hypofractionated and conventional WBI, total and radiotherapy-related health care expenditures, and patient out-of-pocket expenses. Patient and clinical characteristics included year of treatment, age, comorbid disease, prior chemotherapy, axillary lymph node involvement, intensity-modulated radiotherapy, practice setting, and other contextual variables.

Results: Hypofractionated WBI increased from 10.6% (95% CI, 8.8%-12.5%) in 2008 to 34.5% (95% CI, 32.2%-36.8%) in 2013 in the hypofractionation-endorsed cohort and from 8.1% (95% CI, 6.0%-10.2%) in 2008 to 21.2% (95% CI, 18.9%-23.6%) in 2013 in the hypofractionation-permitted cohort. Adjusted mean total health care expenditures in the 1 year after diagnosis were $28,747 for hypofractionated and $31,641 for conventional WBI in the hypofractionation-endorsed cohort (difference, $2894; 95% CI, $1610-$4234; P < .001) and $64,273 for hypofractionated and $72,860 for conventional WBI in the hypofractionation-permitted cohort (difference, $8587; 95% CI, $5316-$12,017; P < .001). Adjusted mean total 1-year patient out-of-pocket expenses were not significantly different between hypofractionated vs conventional WBI in either cohort.

Conclusions and relevance: Hypofractionated WBI after breast conserving surgery increased among women with early-stage breast cancer in 14 US commercial health care plans between 2008 and 2013. However, only 34.5% of patients with hypofractionation-endorsed and 21.2% with hypofractionation-permitted early-stage breast cancer received hypofractionated WBI in 2013.

Conflict of interest statement

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Drs Liu and Barron and Ms Sylwestrzak reported that they are employees of HealthCore, which is a wholly-owned WellPoint subsidiary. Dr Malin reported that she is an employee of WellPoint.

Figures

Figure 1

Definition of Study Cohorts and Reasons for Exclusionsa a Initial inclusion criteria included that women be enrollees of commercial or Medicare Advantage plans, be at least 18 years old, have a diagnosis code for breast cancer, have been treated with lumpectomy, and have any code for radiation therapy appearing within 12 months of lumpectomy, and treated between 2008 and 2013. b Exclusions applied sequentially. Patients could be excluded for more than 1 reason.

Figure 2

Hypofractionated Whole Breast Irradiation After Breast Conserving Surgery Among Patients With Early-Stage Breast Cancer in 14 Commercial Health Plans, 2008 to 2013