title: Factors affecting sentinel lymph node identification rate after neoadjuvant chemotherapy for breast cancer patients enrolled in ACOSOG Z1071 (Alliance).
abstract: OBJECTIVE
  To evaluate factors affecting sentinel lymph node (SLN) identification after neoadjuvant chemotherapy (NAC) in patients with initial node-positive breast cancer.
  
  
  BACKGROUND
  SLN surgery is increasingly used for nodal staging after NAC and optimal technique for SLN identification is important.
  
  
  METHODS
  The American College of Surgeons Oncology Group Z1071 prospective trial enrolled clinical T0-4, N1-2, M0 breast cancer patients. After NAC, SLN surgery and axillary lymph node dissection (ALND) were planned. Multivariate logistic regression modeling assessing factors influencing SLN identification was performed.
  
  
  RESULTS
  Of 756 patients enrolled, 34 women withdrew, 21 were ineligible, 12 underwent ALND only, and 689 had SLN surgery attempted. At least 1 SLN was identified in 639 patients (92.7%: 95% CI: 90.5%-94.6%). Among factors evaluated, mapping technique was the only factor found to impact SLN identification; with use of blue dye alone increasing the likelihood of failure to identify the SLN relative to using radiolabeled colloid +/- blue dye (P = 0.006; OR = 3.82; 95% CI: 1.47-9.92). The SLN identification rate was 78.6% with blue dye alone; 91.4% with radiolabeled colloid and 93.8% with dual mapping agents. Patient factors (age, body mass index), tumor factors (clinical T or N stage), pathologic nodal response to chemotherapy, site of tracer injection, and length of chemotherapy treatment did not significantly affect the SLN identification rate.
  
  
  CONCLUSIONS
  The SLN identification rate after NAC was higher when mapping was performed using radiolabeled colloid alone or with blue dye compared with blue dye alone. Optimal tracer use is important to ensure successful identification of SLN(s) after NAC.
authors: *Mayo Clinic, Rochester, MN †Alliance Statistics and Data Center, Mayo Clinic, Rochester, MN ‡MD Anderson Cancer Center, Houston, TX §University of Pittsburgh, Pittsburgh, PA ¶University of Wisconsin, Madison, WI ‖Columbia University Medical Center, New York, NY **University of Texas Southwestern Medical Center, Dallas, TX ††Carolinas Medical Center, Charlotte, NC; and ‡‡Indiana University Medical Center, Indianapolis, IN.
authors: Judy C
authors: JC
authors: Boughey
authors: Vera J
authors: VJ
authors: Suman
authors: Elizabeth A
authors: EA
authors: Mittendorf
authors: Gretchen M
authors: GM
authors: Ahrendt
authors: Lee G
authors: LG
authors: Wilke
authors: Bret
authors: B
authors: Taback
authors: A Marilyn
authors: AM
authors: Leitch
authors: Teresa S
authors: TS
authors: Flippo-Morton
authors: Henry M
authors: HM
authors: Kuerer
authors: Monet
authors: M
authors: Bowling
authors: Kelly K
authors: KK
authors: Hunt
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D003102:Colloids; D004396:Coloring Agents; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D021701:Sentinel Lymph Node Biopsy
chemical_list: D003102:Colloids; D004396:Coloring Agents; D019275:Radiopharmaceuticals