title: Determining breast cancer axillary surgery within the surveillance epidemiology and end results-Medicare database.
abstract: BACKGROUND
  Use of sentinel lymph node biopsy (SLNB) is under-reported by cancer registries' "Scope of Regional Lymph Node Surgery" variable. In 2011, the Surveillance Epidemiology and End Results (SEER) Program recommended against its use to determine extent of axillary surgery, leaving a gap in the utilization of claims data for breast cancer research. The objective was to develop an algorithm using SEER registry and claims data to classify extent of axillary surgery for breast cancer.
  
  
  METHODS
  We analyzed data for 24,534 breast cancer patients. CPT codes and number of examined lymph nodes classified the extent of axillary surgery. The final algorithm was validated by comparing the algorithm derived extent of axillary surgery to direct chart review for 100 breast cancer patients treated at our breast center.
  
  
  RESULTS
  Using the algorithm, 13% had no axillary surgery, 56% SLNB and 31% axillary lymph node dissection (ALND). SLNB was performed in 77% of node negative patients and ALND in 72% of node positive. In our validation study, concordance between algorithm and direct chart review was 97%.
  
  
  CONCLUSIONS
  Given recognized inaccuracies in cancer registries' "Scope of Regional Lymph Node Surgery" variable, these findings have high utility for health services researchers studying breast cancer treatment.
authors.affiliation: Department of Surgery, UW Madison School of Medicine and Public Health, Madison, Wisconsin.
authors.forename: Ryan K
authors.initials: RK
authors.lastname: Schmocker
authors.forename: Holly
authors.initials: H
authors.lastname: Caretta-Weyer
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Weiss
authors.forename: Katie
authors.initials: K
authors.lastname: Ronk
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Havlena
authors.forename: Noelle K
authors.initials: NK
authors.lastname: Loconte
authors.forename: Marquita
authors.initials: M
authors.lastname: Decker
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Smith
authors.forename: Caprice C
authors.initials: CC
authors.lastname: Greenberg
authors.forename: Heather B
authors.initials: HB
authors.lastname: Neuman
mesh_terms: D000465:Algorithms; D001365:Axilla; D001943:Breast Neoplasms / Q000453:epidemiology / Q000601:surgery*; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008408:Mastectomy; D006278:Medicare / Q000706:statistics & numerical data; D018579:Patient Selection; D011379:Prognosis; D018426:SEER Program; D021701:Sentinel Lymph Node Biopsy; D014481:United States / Q000453:epidemiology
keywords: SEER-Medicare; axillary surgery; breast cancer