title: Evolution of axillary nodal staging in breast cancer: clinical implications of the ACOSOG Z0011 trial.
abstract: BACKGROUND
  Management of the axilla in breast cancer patients has evolved from routine axillary lymph node dissection (ALND) for all patients to a highly selective approach based on the assessment of the sentinel lymph nodes (SLNs) as well as tumor and patient characteristics. Although ALND continues to have an important role in staging and regional control for many breast cancer patients, recent trial results question the need for routine ALND in patients who have positive SLNs.
  
  
  METHODS
  Not all axillary disease becomes clinically detectable or relevant with respect to recurrence and survival. Therefore, recent trends indicate that many surgeons have omitted ALND in subgroups of patients, particularly those with clinically node-negative, SLN-positive, early-stage breast cancer undergoing breast-conserving therapy with postoperative irradiation. This review explores trends in axillary management, focusing primarily on the clinical implications of the results from the American College of Surgeons Oncology Group (ACOSOG) Z0011 randomized controlled trial.
  
  
  RESULTS
  According to the results of the ACOSOG Z0011 trial, the use of SLN dissection alone did not result in inferior survival compared with ALND in patients with limited SLN disease treated with breast-conserving therapy. This subgroup of women was spared the morbidity associated with ALND. However, several points of debate, including the smaller than anticipated sample size, the older study population, and the length of follow-up, suggest caution when applying these findings to all women with breast cancer.
  
  
  CONCLUSIONS
  Although the findings of ACOSOG Z0011 are impressive, in clinical practice they are applicable to a limited number of women with breast cancer: those with T1-2 primary tumors with clinically negative axilla and 1 to 2 positive SLNs undergoing breast-conserving surgery and adjuvant whole-breast irradiation. The next generation of clinical trials may answer some of the remaining questions regarding how best to manage the axilla in additional subsets of patients undergoing treatment of breast cancer.
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Miraj
authors.initials: M
authors.lastname: Shah-Khan
authors.forename: Judy C
authors.initials: JC
authors.lastname: Boughey
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D015412:Mastectomy, Segmental; D009367:Neoplasm Staging; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D016896:Treatment Outcome