title: Intraoperative sentinel node biopsy by one-step nucleic acid amplification (OSNA) avoids axillary lymphadenectomy in women with breast cancer treated with neoadjuvant chemotherapy.
abstract: BACKGROUND
  There is no evidence that supports the recommendation of sentinel lymph node biopsy (SLNB) in patients with breast cancer who have treated with neoadjuvant chemotherapy (NAC) to downsize tumors in order to allow breast conservation surgery, because NAC induces anatomical alterations of the lymphatic drainage. We evaluated the effectiveness of SLNB using intraoperative one-step nucleic acid amplification (OSNA) method to detect microscopic metastases or isolated tumor cells after NAC in patients with clinically negative axillary nodes at initial presentation.
  
  
  METHODS
  We evaluated in patients with breast cancer and clinically negative axilla at presentation, the effectiveness of SLNB by OSNA after NAC (71 patients) or prior to NAC (40 patients).
  
  
  RESULTS
  The rate of SLN identification was 100% in both groups. 17 women with SLNB prior to systemic treatment showed positive nodes (14 macrometastases and 3 micrometastases), and positive SLNB were detected in 15 women with SLNB after NAC, which were 14 macrometastases and 1 micrometastase. The negative predictive value of ultrasonography was 57.5% in patients with SLNB prior to neoadjuvant therapy and 78.9% in patients with chemotherapy followed by SLNB.
  
  
  CONCLUSIONS
  Intraoperative SLNB using OSNA in women with clinically negative axillary lymph nodes at initial presentation who received NAC could predict axillary status with high accuracy. Also it allows us to take decisions about the indication or not to perform an axillary dissection at the moment, thus avoiding delay in the administration of chemotherapy and benefiting the patients from a single surgical procedure.
authors.affiliation: Breast Pathology Unit, Department of Surgery, Hospital Complex of Jaén, Av. Ejército Español, 10, Jaén 23 007, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Navarro-Cecilia
authors.forename: B
authors.initials: B
authors.lastname: Dueñas-Rodríguez
authors.forename: C
authors.initials: C
authors.lastname: Luque-López
authors.forename: M J
authors.initials: MJ
authors.lastname: Ramírez-Expósito
authors.forename: J
authors.initials: J
authors.lastname: Martínez-Ferrol
authors.forename: A
authors.initials: A
authors.lastname: Ruíz-Mateas
authors.forename: C
authors.initials: C
authors.lastname: Ureña
authors.forename: M P
authors.initials: MP
authors.lastname: Carrera-González
authors.forename: M D
authors.initials: MD
authors.lastname: Mayas
authors.forename: J M
authors.initials: JM
authors.lastname: Martínez-Martos
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D008197:Lymph Node Excision / Q000379:methods; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D021141:Nucleic Acid Amplification Techniques; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Breast cancer; Lymphadenectomy; Neoadjuvant chemotherapy; OSNA; Sentinel node