title: Breast cancer subtypes can be determinant in the decision making process to avoid surgical axillary staging: A retrospective cohort study.
abstract: BACKGROUND
  The need for performing axillary lymph-node dissection in early breast cancer when the sentinel lymph node (SLN) is positive has been questioned in recent years. The purpose of this study was to identify a low-risk subgroup of early breast cancer patients in whom surgical axillary staging could be avoided, and to assess the probability of having a positive lymph-node (LN).
  
  
  METHODS
  We evaluated the cohort of 612 consecutive women affected by early breast cancer. We considered age, tumor size, histological grade, vascular invasion, lymphatic invasion and cancer subtype (Luminal A, Luminal B HER-2+, Luminal B HER-2-, HER-2+, and Triple Negative) as variables for univariate and multivariate analyses to assess probability of there being a positive SLN o nonsentinel lymph node (NSLN). Chi-square, Fisher's Exact test and Student's t tests were used to investigate the relationship between variables; whereas logit models were used to estimate and quantify the strength of the relationship among some covariates and SLN or the number of metastases.
  
  
  RESULTS
  A significant positive effect of vascular invasion and lymphatic invasion (odds ratios are 4 and 6), and a negative effect of TN (odds ratios is 10) were noted. With respect to positive NSLN, size alone has a significant (positive) effect on tumor presence, but focusing on the number of metastases, also age has a (negative) significant effect.
  
  
  CONCLUSIONS
  This work shows correlation between subtypes and the probability of having positive SLN. Patients not expressing vascular invasion, lymphatic invasion and, moreover, a triple-negative tumor subtype may be good candidates for breast conservative surgery without axillary surgical staging.
authors.affiliation: Department of Surgical, Oncological and Stomatological Sciences, Policlinico Hospital "Paolo Giaccone", University of Palermo, Via del Vespro, 129, 90127 Palermo, Italy. Electronic address: antonio.marrazzo@unipa.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Marrazzo
authors.affiliation: Department of Economics, Business and Statistics Sciences, University of Palermo, Viale delle Scienze, 90128 Palermo, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Boscaino
authors.affiliation: Department of Surgical, Oncological and Stomatological Sciences, Policlinico Hospital "Paolo Giaccone", University of Palermo, Via del Vespro, 129, 90127 Palermo, Italy. Electronic address: emilia.marrazzo@hotmail.it.
authors.forename: Emilia
authors.initials: E
authors.lastname: Marrazzo
authors.affiliation: Breast Unit, Clinic "Macchiarella", Viale Regina Margherita, 25, 90138 Palermo, Italy.
authors.forename: Pietra
authors.initials: P
authors.lastname: Taormina
authors.affiliation: Division of Breast Surgery, European Institute of Oncology, Via Giuseppe Ripamonti, 435, 20141 Milan, Italy. Electronic address: antonio.toesca@ieo.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Toesca
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D000066491:Clinical Decision-Making; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy; D064726:Triple Negative Breast Neoplasms / Q000473:pathology
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: Axillary surgery; Biological prognostic factors; Breast cancer; Sentinel lymph node biopsy