title: Predictive factors of isolated tumor cells and micrometastases in axillary lymph nodes in breast cancer.
abstract: BACKGROUND
  Since the introduction of the sentinel lymph node biopsy (SLNB) in patients with breast cancer, micrometastases and isolated tumor cells are detected frequently in the SLN. As such, they offer an opportunity to study the development of regional metastases in breast cancer.
  
  
  METHODS
  Between June 1999 and November 2010 1418 patients with cT1-2N0 breast cancer underwent SLNB. Primary tumor characteristics and information regarding regional lymph node involvement were collected prospectively. Patients were categorized into four levels of lymph node involvement: pN0, pN0(i+), pN1mi and pN ≥ 1a. An univariate analysis and a binary logistic regression analysis were performed to assess the relation between patient- and tumor characteristics and lymph node involvement.
  
  
  RESULTS
  Increasing tumor size and younger age were associated with a higher risk of pN1mi and pN ≥ 1a and a lower chance of pN0 and pN0(i+). Triple negative molecular subtype was associated with a decreased risk of pN1mi and pN ≥ 1a. Tumor size was positively related to overall occurrence of regional lymph node metastases in a linear manner.
  
  
  CONCLUSIONS
  Patients with larger tumors, no triple negative disease, and younger age showed a decreased chance of both pN0 and pN0(i+) and an increased risk of both pN1mi and pN ≥ 1a. There seems to be a gradual shift in risk pattern from pN0 to pN0(i+) to pN1mi and to pN ≥ 1a-disease. The presence of the smallest metastases remained fairly constant over time when compared to macrometastases. This constant presence suggests that the risk of seeding and outgrowth of metastases remains constant over time.
authors: Diakonessenhuis Utrecht, Department of Surgery, Diakonessenhuis, Bosboomstraat 1, 3582 KE Utrecht, The Netherlands. Electronic address: eve_madsen@hotmail.com.
authors: Eva V E
authors: EV
authors: Madsen
authors: Sjoerd G
authors: SG
authors: Elias
authors: Thijs
authors: T
authors: van Dalen
authors: Pouline M P
authors: PM
authors: van Oort
authors: Joost
authors: J
authors: van Gorp
authors: Paul D
authors: PD
authors: Gobardhan
authors: Vivian
authors: V
authors: Bongers
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D061206:Neoplasm Micrometastasis / Q000473:pathology*; D009367:Neoplasm Staging; D018570:Risk Assessment; D012307:Risk Factors; D021701:Sentinel Lymph Node Biopsy; D064726:Triple Negative Breast Neoplasms / Q000473:pathology; D047368:Tumor Burden; D055815:Young Adult
keywords: Breast cancer; Isolated tumor cells; Lymph node metastases; Micrometastases; Predictive factors; Tumor characteristics