title: The St. Gallen surrogate classification for breast cancer subtypes successfully predicts tumor presenting features, nodal involvement, recurrence patterns and disease free survival.
abstract: OBJECTIVE
  To evaluate how the St. Gallen intrinsic subtype classification for breast cancer surrogates predicts disease features, recurrence patterns and disease free survival.
  
  
  METHODS
  Subtypes were classified by immunohistochemical staining according to St. Gallen subtypes classification in a 5-tyre system: luminal A, luminal B HER2-neu negative, luminal B HER2-neu positive, HER2-neu non luminal or basal-like. Data were obtained from the records of patients with invasive breast cancer treated at our institution. Recurrence data and site of first recurrence were recorded. The chi(2) test, analysis of variance, and multivariate logistic regression analysis were used to determine associations between surrogates and clinicopathologic variables.
  
  
  RESULTS
  A total of 2.984 tumors were classifiable into surrogate subtypes. Significant differences in age, tumor size, nodal involvement, nuclear grade, multicentric/multifocal disease (MF/MC), lymphovascular invasion, and extensive intraductal component (EIC) were observed among surrogates (p < 0.0001). After adjusting for confounding factors surrogates remained predictive of nodal involvement (luminal B HER2-neu pos. OR = 1.49 p = 0.009, non-luminal HER2-neu pos. OR = 1.61 p = 0.015 and basal-like OR = 0.60, p = 0.002) while HER2-neu positivity remained predictive of EIC (OR = 3.10, p < 0.0001) and MF/MC (OR = 1.45, p = 0.02). Recurrence rates differed among the surrogates and were time-dependent (p = 0.001) and site-specific (p < 0.0001).
  
  
  CONCLUSIONS
  The St. Gallen 5-tyre surrogate classification for breast cancer subtypes accurately predicts breast cancer presenting features (with emphasis on prediction of nodal involvement), recurrence patterns and disease free survival.
authors.affiliation: Berlin Breast Center Kurfürstendamm, Kurfürstendamm 216, 10719 Berlin, Germany. Electronic address: ines.mv@gmail.com.
authors.forename: Ines
authors.initials: I
authors.lastname: Vasconcelos
authors.affiliation: Martin Luther Clinic Breast Center, Caspar-Theyß-Straße 27-31, 14193 Berlin, Germany.
authors.forename: Afsana
authors.initials: A
authors.lastname: Hussainzada
authors.affiliation: Gemeinschaftspraxis für Pathologie am Bundeswehrkrankenhaus, Scharnhorststrasse 13, 10115 Berlin, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Berger
authors.affiliation: Gemeinschaftspraxis für Pathologie am Bundeswehrkrankenhaus, Scharnhorststrasse 13, 10115 Berlin, Germany.
authors.forename: Ellen
authors.initials: E
authors.lastname: Fietze
authors.affiliation: Gemeinschaftspraxis für Pathologie am Bundeswehrkrankenhaus, Scharnhorststrasse 13, 10115 Berlin, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Linke
authors.affiliation: Martin Luther Clinic Breast Center, Caspar-Theyß-Straße 27-31, 14193 Berlin, Germany.
authors.forename: Friederike
authors.initials: F
authors.lastname: Siedentopf
authors.affiliation: Berlin Breast Center Kurfürstendamm, Kurfürstendamm 216, 10719 Berlin, Germany.
authors.forename: Winfried
authors.initials: W
authors.lastname: Schoenegg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000737:chemistry / Q000145:classification* / Q000473:pathology; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016015:Logistic Models; D008207:Lymphatic Metastasis; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D011237:Predictive Value of Tests; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D055815:Young Adult
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: Breast cancer; Disease free survival; Immunohistochemical surrogates; Molecular subtypes; Nodal involvement; Recurrence