title: Relevant impact of central pathology review on nodal classification in individual breast cancer patients.
abstract: BACKGROUND
  In the MIRROR study, pN0(i + ) and pN1mi were associated with reduced 5-year disease-free survival (DFS) compared with pN0. Nodal status (N-status) was assessed after central pathology review and restaging according to the sixth AJCC classification. We addressed the impact of pathology review.
  
  
  METHODS
  Early favorable primary breast cancer patients, classified pN0, pN0(i + ), or pN1(mi) by local pathologists after sentinel node procedure, were included. We assessed the impact of pathology review on N-status (n = 2842) and 5-year DFS for those without adjuvant therapy (n = 1712).
  
  
  RESULTS
  In all, 22% of the 1082 original pN0 patients was upstaged. Of the 623 original pN0(i + ) patients, 1% was downstaged, 26% was upstaged. Of 1137 patients staged pN1mi, 15% was downstaged, 11% upstaged. Originally, 5-year DFS was 85% for pN0, 74% for pN0(i + ), and 73% for pN1mi; HR 1.70 [95% confidence interval (CI) 1.27-2.27] and HR 1.57 (95% CI 1.16-2.13), respectively, compared with pN0. By review staging, 5-year DFS was 86% for pN0, 77% for pN0(i + ), 77% for pN1mi, and 74% for pN1 + .
  
  
  CONCLUSIONS
  Pathology review changed the N-classification in 24%, mainly upstaging, with potentially clinical relevance for individual patients. The association of isolated tumor cells and micrometastases with outcome remained unchanged. Quality control should include nodal breast cancer staging.
authors.affiliation: Department of Internal Medicine, Division of Medical Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht.
authors.forename: J H M J
authors.initials: JHMJ
authors.lastname: Vestjens
authors.affiliation: Department of Internal Medicine, Division of Medical Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht.
authors.forename: M J
authors.initials: MJ
authors.lastname: Pepels
authors.affiliation: Department of Internal Medicine, Division of Medical Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht.
authors.forename: M
authors.initials: M
authors.lastname: de Boer
authors.affiliation: Department of Epidemiology, Biostatistics and HTA, Radboud University Medical Centre Nijmegen, Nijmegen.
authors.forename: G F
authors.initials: GF
authors.lastname: Borm
authors.affiliation: Department of Pathology, University Medical Centre Utrecht, Utrecht.
authors.forename: C H M
authors.initials: CHM
authors.lastname: van Deurzen
authors.affiliation: Department of Pathology, University Medical Centre Utrecht, Utrecht.
authors.forename: P J
authors.initials: PJ
authors.lastname: van Diest
authors.affiliation: Department of Epidemiology, Biostatistics and HTA, Radboud University Medical Centre Nijmegen, Nijmegen.
authors.forename: J A A M
authors.initials: JAAM
authors.lastname: van Dijck
authors.affiliation: Department of Epidemiology, Biostatistics and HTA, Radboud University Medical Centre Nijmegen, Nijmegen.
authors.forename: E M M
authors.initials: EMM
authors.lastname: Adang
authors.affiliation: Department of Internal Medicine, Division of Medical Oncology, Leiden University Medical Centre, Leiden.
authors.forename: J W R
authors.initials: JWR
authors.lastname: Nortier
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute, Amsterdam.
authors.forename: E J Th
authors.initials: EJT
authors.lastname: Rutgers
authors.affiliation: Department of Internal Medicine, Division of Medical Oncology.
authors.forename: C
authors.initials: C
authors.lastname: Seynaeve
authors.affiliation: Department of Surgery, Erasmus Medical Centre-Daniel den Hoed Cancer Centre, Rotterdam.
authors.forename: M B E
authors.initials: MBE
authors.lastname: Menke-Pluymers
authors.affiliation: Department of Pathology, Radboud University Medical Centre Nijmegen, Nijmegen, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Bult
authors.affiliation: Department of Internal Medicine, Division of Medical Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht. Electronic address: vcg.tjan.heijnen@mumc.nl.
authors.forename: V C G
authors.initials: VCG
authors.lastname: Tjan-Heijnen
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D009367:Neoplasm Staging; D015996:Survival Rate