title: Analysis of dendritic cells in tumor-free and tumor-containing sentinel lymph nodes from patients with breast cancer.
abstract: BACKGROUND
  Sentinel lymph node (SLN) biopsy allows identification of the first lymph node into which a primary tumor drains. In breast cancer, identification of tumor cells in the SLNs is a predictor of the tumor's metastatic potential. In the present article, we tested the hypotheses that a positive immune response can occur in tumor-free SLNs and that the activation state of dendritic cells (DCs), the major antigen presenting cells within SLNs, predicts the immune status and metastatic potential of the tumor.
  
  
  METHODS
  Fifty paraffin-embedded SLN sections, 25 tumor-free and 25 tumor-containing, from patients with breast cancer were analyzed by immunohistochemistry to determine the immune maturation state of their DCs. In addition, 12 lymph nodes from noncancer-containing breasts were analyzed. Tissues were stained with antibodies against CD3, MHC class II, CD1a, CD83, IL-10, and IL-12. Mature DCs were defined by CD83 expression and immature DCs by CD1a expression.
  
  
  RESULTS
  We found a trend toward higher numbers of mature CD83-positive DCs in tumor-free SLNs than in tumor-containing SLNs (P = 0.07). In addition, tumor-free SLNs were more likely to contain cells expressing IL-10 (P = 0.02) and, to a lesser extent, IL-12 (P = 0.12). In contrast, when all SLNs, both tumor-free and tumor-containing, were compared with uninvolved lymph nodes, the numbers of mature and immature DCs were similar.
  
  
  CONCLUSIONS
  Our results suggest tumor-free SLNs are immunologically competent and potentially a site of tumor-specific T-cell activation, as evidenced by the presence of greater numbers of mature DCs and cytokine-producing cells in tumor-free SLNs.
authors.affiliation: Department of Bioimmunotherapy, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA. npoindex@mdanderson.org
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Poindexter
authors.forename: Aysegul
authors.initials: A
authors.lastname: Sahin
authors.forename: Kelly K
authors.initials: KK
authors.lastname: Hunt
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Grimm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001940:Breast / Q000473:pathology / Q000502:physiology; D001943:Breast Neoplasms / Q000473:pathology*; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000502:physiology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000737:chemistry / Q000166:cytology* / Q000473:pathology*; D008875:Middle Aged; D021701:Sentinel Lymph Node Biopsy
chemical_list: D016207:Cytokines