title: Geographic Disparity in the Use of Hypofractionated Radiation Therapy Among Elderly Women Undergoing Breast Conservation for Invasive Breast Cancer.
abstract: To evaluate geographic heterogeneity in the delivery of hypofractionated radiation therapy (RT) for breast cancer among Medicare beneficiaries across the United States.
  
  
  
  We identified 190,193 patients from the Centers for Medicare and Medicaid Services Chronic Conditions Warehouse. The study included patients aged >65 years diagnosed with invasive breast cancer treated with breast conservation surgery followed by radiation diagnosed between 2000 and 2012. We analyzed data by hospital referral region based on patient residency ZIP code. The proportion of women who received hypofractionated RT within each region was analyzed over the study period. Multivariable logistic regression models identified predictors of hypofractionated RT.
  
  
  
  Over the entire study period we found substantial geographic heterogeneity in the use of hypofractionated RT. The proportion of women receiving hypofractionated breast RT in individual hospital referral regions varied from 0% to 61%. We found no correlation between the use of hypofractionated RT and urban/rural setting or general geographic region. The proportion of hypofractionated RT increased in regions with higher density of radiation oncologists, as well as lower total Medicare reimbursements.
  
  
  
  This study demonstrates substantial geographic heterogeneity in the use of hypofractionated RT among elderly women with invasive breast cancer treated with lumpectomy in the United States. This heterogeneity persists despite clinical data from multiple randomized trials proving efficacy and safety compared with standard fractionation, and highlights possible inefficiency in health care delivery.
authors.affiliation: Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California.
authors.forename: Erin F
authors.initials: EF
authors.lastname: Gillespie
authors.affiliation: Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California.
authors.forename: Rayna K
authors.initials: RK
authors.lastname: Matsuno
authors.affiliation: Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California.
authors.forename: Beibei
authors.initials: B
authors.lastname: Xu
authors.affiliation: Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Triplett
authors.affiliation: Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Hwang
authors.affiliation: Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California.
authors.forename: Isabel J
authors.initials: IJ
authors.lastname: Boero
authors.affiliation: Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California.
authors.forename: John P
authors.initials: JP
authors.lastname: Einck
authors.affiliation: Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California.
authors.forename: Catheryn
authors.initials: C
authors.lastname: Yashar
authors.affiliation: Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California. Electronic address: j2murphy@ucsd.edu.
authors.forename: James D
authors.initials: JD
authors.lastname: Murphy
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000628:therapy*; D005260:Female; D005843:Geography; D015276:Health Care Rationing / Q000706:statistics & numerical data*; D054625:Healthcare Disparities / Q000706:statistics & numerical data*; D006801:Humans; D015412:Mastectomy, Segmental / Q000706:statistics & numerical data*; D009361:Neoplasm Invasiveness; D059351:Organ Sparing Treatments / Q000706:statistics & numerical data; D015995:Prevalence; D000069473:Radiation Dose Hypofractionation; D018714:Radiotherapy, Adjuvant / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D012424:Rural Population; D014481:United States / Q000453:epidemiology; D014505:Urban Population / Q000706:statistics & numerical data; D014600:Utilization Review; D016387:Women's Health / Q000706:statistics & numerical data