title: Axillary node staging for microinvasive breast cancer: is it justified?
abstract: BACKGROUND
  The natural history and role of axillary staging in microinvasive breast cancer (DCISM) remains controversial. We report clinical characteristics and outcome in patients with DCISM, focusing on the role of sentinel lymph node (SLN) biopsy.
  
  
  METHODS
  From our prospective database we retrospectively identified 112 patients with DCISM who underwent SLN biopsy between 1996 and 2004 at our institution. Median follow-up was 6 years.
  
  
  RESULTS
  We found positive SLN in 12% of patients (14 of 112): macrometastasis in 2.7% (3 of 112) and micrometastases or isolated tumor cells (ITC) in 10% (11 of 112). We performed axillary dissection (ALND) in all patients with macrometastasis (3 of 3), finding additional positive nodes in 66% (2 of 3), and in 27% of those with micrometastases/ITCs (3 of 11), finding no additional positive nodes. Among 98 patients with negative SLN (38% of whom received systemic therapy), there were 5 locoregional recurrences (1 in the ipsilateral axilla, 4 in the ipsilateral breast, all DCIS) and 4 contralateral second primary cancers. Among 14 patients with positive SLN (82 % of whom received systemic adjuvant therapy), there were no locoregional or distant recurrences.
  
  
  CONCLUSIONS
  Our results suggest that SLN biopsy may be justified for DCISM, but is clearly most beneficial to identify a very small subset of DCISM patients (2.7%, with SLN macrometastasis) who could benefit from systemic adjuvant therapy. The benefit of SLN biopsy for patients with SLN micrometastases/ITCs (pN0mi or pN0(i+)) is uncertain, and in these cases ALND does not appear to be warranted. We suggest a wider reappraisal of routine SLN biopsy for DCISM.
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA. lyonsj@mskcc.org
authors.forename: John M
authors.initials: JM
authors.lastname: Lyons
authors.forename: Michelle
authors.initials: M
authors.lastname: Stempel
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Van Zee
authors.forename: Hiram S
authors.initials: HS
authors.lastname: Cody
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D018567:Breast Neoplasms, Male / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D002278:Carcinoma in Situ / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy / Q000556:secondary* / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D061206:Neoplasm Micrometastasis; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009367:Neoplasm Staging; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy