title: Differences in sentinel lymph node pathology protocols lead to differences in surgical strategy in breast cancer patients.
abstract: BACKGROUND
  Internationally, there is no consensus on the pathology protocol to be used to examine the sentinel lymph node (SN). At present, therefore, various hospitals use different SN pathology protocols of which the effect has not been fully elucidated. We hypothesized that differences between hospitals in SN pathology protocols affect subsequent surgical treatment strategies.
  
  
  METHODS
  Patients from four hospitals (A-D) were prospectively registered when they underwent an SN biopsy. In hospitals A, B, and C, three levels of the SN were examined pathologically, whereas in hospital D, at least seven additional levels were examined. In the absence of apparent metastases with hematoxylin and eosin examination, immunohistochemical examination was performed in all four hospitals.
  
  
  RESULTS
  In total, 541 eligible patients were included. In hospital D, more patients were diagnosed with a positive SN (P < .001) as compared with hospitals A, B, and C, mainly because of increased detection of isolated tumor cells. This led to more completion axillary lymph node dissections in hospital D (66.3% of patients (P < .0001), compared with 29.0% in hospitals A, B, and C combined). Positive non-SNs were detected in 13.9% of patients in hospital D, compared with 9.7% in hospitals A, B, and C (P = .70). That is, in 52.4% of patients in hospital D, a negative completion axillary lymph node dissection was performed, compared with 19.3% of patients in hospitals A, B, and C combined.
  
  
  CONCLUSIONS
  Differences in SN pathology protocols between hospitals do have a substantial effect on SN findings and subsequent surgical treatment strategies. Whether ultrastaging and, thus, additional surgery can offer better survival remains to be determined.
authors.affiliation: Department of Surgery, Radboud University Nijmegen Medical Center, NL-6500, HB, Nijmegen, The Netherlands. m.bolster@chir.umcn.nl
authors.forename: Marieke J
authors.initials: MJ
authors.lastname: Bolster
authors.forename: Peter
authors.initials: P
authors.lastname: Bult
authors.forename: René F M
authors.initials: RF
authors.lastname: Schapers
authors.forename: Jos W R
authors.initials: JW
authors.lastname: Meijer
authors.forename: Luc J A
authors.initials: LJ
authors.lastname: Strobbe
authors.forename: Charles L H
authors.initials: CL
authors.lastname: van Berlo
authors.forename: Jean H G
authors.initials: JH
authors.lastname: Klinkenbijl
authors.forename: Petronella G M
authors.initials: PG
authors.lastname: Peer
authors.forename: Theo
authors.initials: T
authors.lastname: Wobbes
authors.forename: Vivianne C G
authors.initials: VC
authors.lastname: Tjan-Heijnen
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology / Q000601:surgery*; D002985:Clinical Protocols / Q000592:standards*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010336:Pathology / Q000592:standards*; D011446:Prospective Studies; D021701:Sentinel Lymph Node Biopsy