title: Role of total tumour load of sentinel lymph node on survival in early breast cancer patients.
abstract: BACKGROUND
  Axillary staging (pN) is considered one of the most important prognostic factors in breast cancer patients. However, the Z0011 study data drastically reduced the number of surgical axillary dissections in a selected group of patients, limiting the prognostic information relating to axillary involvement to the sentinel lymph node (SLN). It is known that there is a relationship between SLN total tumour load (TTL) and axillary involvement. The objective of this study is to analyse the relationship between the TTL and outcomes in patients with early stage breast cancer.
  
  
  METHODS
  clinicopathological and follow-up data were collected from 950 patients with breast cancer between 2009 and 2010 on whom SLN analysis was conducted by molecular methods (One Step Nucleic Acid Amplification, Sysmex, Kobe, Japan).
  
  
  RESULTS
  TTL (defined as the total number of CK19 mRNA copies in all positive SLN) correlates with disease free survival (HR, 1.08; p = 0.000004), with local recurrence disease free survival (HR = 1.07; p = 0.0014) and overall survival (HR: 1.08, p = 0.0032), clearly defining a low-risk group (TTL <2.5 × 104CK19 mRNA copies/μL) versus a high-risk group (>2.5 × 104CK 19 mRNA copies/μL).
  
  
  CONCLUSIONS
  SLN TTL permits the differentiation between two patient groups in terms of DFS and OS, independently of axillary staging (pN), age and tumour characteristics (size, grade, lymphovascular invasion). This new data confirms the clinical value of low axillary involvement and could partially replace the information that staging of the entire axilla provides in patients on whom no axillary lymph node dissection is performed.
authors.affiliation: Pathology Department, Vall d'Hebron University Hospital, Barcelona, Spain; Morphological Sciences Department, Universidad Autónoma de Barcelona, Spain. Electronic address: vpeg@vhebron.net.
authors.forename: Vicente
authors.initials: V
authors.lastname: Peg
authors.affiliation: Pathology Department, Vall d'Hebron University Hospital, Barcelona, Spain; Morphological Sciences Department, Universidad Autónoma de Barcelona, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Sansano
authors.affiliation: Pathology Department, Virgen del Rocío University Hospital, Sevilla, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Vieites
authors.affiliation: Pathology Department, Hospital Lluis Alcanys, Xàtiva, Spain.
authors.forename: Laia
authors.initials: L
authors.lastname: Bernet
authors.affiliation: Pathology Department, Hospital de la Ribera, Alcira, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Cano
authors.affiliation: Pathology Department, Hospital de Navarra, Pamplona, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Córdoba
authors.affiliation: Pathology Department, Salamanca University Hospital, Spain.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Sancho
authors.affiliation: Pathology Department, Complejo Hospitalario de Jaén, Spain.
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Martín
authors.affiliation: Pathology Department, Hospital Arnau de Vilanova, Lérida, Spain.
authors.forename: Felip
authors.initials: F
authors.lastname: Vilardell
authors.affiliation: Pathology Department, Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Cazorla
authors.affiliation: Breast Cancer Unit, Vall d'Hebron University Hospital, Barcelona, Spain.
authors.forename: Martín
authors.initials: M
authors.lastname: Espinosa-Bravo
authors.affiliation: Medical Oncology Department, Baselga Institute of Oncology, Quiron Hospital, Barcelona, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Pérez-García
authors.affiliation: Medical Oncology Department, Ramón y Cajal University Hospital, Madrid, Spain; Vall d'Hebron Oncology Institute, Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Cortés
authors.affiliation: Breast Cancer Unit, Vall d'Hebron University Hospital, Barcelona, Spain.
authors.forename: Isabel T
authors.initials: IT
authors.lastname: Rubio
authors.affiliation: Pathology Department, Vall d'Hebron University Hospital, Barcelona, Spain; Morphological Sciences Department, Universidad Autónoma de Barcelona, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Ramón Y Cajal
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000401:mortality* / Q000473:pathology*; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D053539:Keratin-19 / Q000235:genetics; D008137:Longitudinal Studies; D008197:Lymph Node Excision / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis; D000071036:Sentinel Lymph Node / Q000473:pathology*; D047368:Tumor Burden / Q000502:physiology*
chemical_list: D053539:Keratin-19; D012333:RNA, Messenger
keywords: Breast cancer; Prognosis; Sentinel lymph node; Total tumour load