title: Does breast tumor location influence success of sentinel lymph node biopsy?
abstract: BACKGROUND
  Controversy exists regarding the influence of sentinel lymph node (SLN) mapping technique or patient variables on the success rate of SLN mapping. We undertook a prospective study in a single institution series to evaluate multiple variables that could adversely affect SLN identification rates.
  
  
  METHODS
  Data were collected on 174 patients who underwent 177 SLN mapping procedures followed by axillary dissection from October 1996 through January 2000. Patient demographics, body mass index (BMI), biopsy method, tumor size, palpability, and location were recorded. SLNs were identified by blue dye only (n = 31), Tc-99m sulfur colloid only (n = 34), or combined techniques (n = 112). Data were analyzed by logistic regression analysis and expressed as the probability of failure to map the SLN.
  
  
  RESULTS
  SLNs were identified successfully in 150 of 177 procedures (85%) with a false negative rate of 3.7%. Mapping success reached 93% using combination blue dye and isotope. Variables found to adversely affect SLN mapping success and the odds ratio of failure (OR) included lower inner quadrant (LIQ) location (OR 35.6), blue dye only (OR 42.4), BMI >30 and upper outer quadrant (UOQ) location (OR 14.6), and nonpalpable UIQ location (OR 25). LIQ location adversely affects mapping success independent of technique, tumor size, or obesity. Obesity and nonpalpability were adverse factors when tumors were located in the UOQ and UIQ, respectively. Age, biopsy technique, and tumor diameter did not affect SLN mapping success.
  
  
  CONCLUSIONS
  SLN mapping success is influenced by technique and tumor location, with best results achieved using combined techniques and for lesions located in quadrants other than the LIQ. Obesity and tumor palpability influence success in the context of tumor location.
authors.affiliation: Department of Surgery, Medical College of Wisconsin, Milwaukee, USA.
authors.forename: Gretchen M
authors.initials: GM
authors.lastname: Ahrendt
authors.forename: Prakash
authors.initials: P
authors.lastname: Laud
authors.forename: Judy
authors.initials: J
authors.lastname: Tjoe
authors.forename: Dan
authors.initials: D
authors.lastname: Eastwood
authors.forename: Alonzo P
authors.initials: AP
authors.lastname: Walker
authors.forename: Mary F
authors.initials: MF
authors.lastname: Otterson
authors.forename: Philip N
authors.initials: PN
authors.lastname: Redlich
mesh_terms: D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology*; D018567:Breast Neoplasms, Male / Q000473:pathology*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012394:Rosaniline Dyes; D021701:Sentinel Lymph Node Biopsy; D013671:Technetium Tc 99m Sulfur Colloid
chemical_list: D019275:Radiopharmaceuticals; D012394:Rosaniline Dyes; C025484:iso-sulfan blue; D013671:Technetium Tc 99m Sulfur Colloid