title: Immunoglobulin kappa C predicts overall survival in node-negative breast cancer.
abstract: BACKGROUND
  Biomarkers of the immune system are currently not used as prognostic factors in breast cancer. We analyzed the association of the B cell/plasma cell marker immunoglobulin kappa C (IGKC) and survival of untreated node-negative breast cancer patients.
  
  
  METHODS
  IGKC expression was evaluated by immunostaining in a cohort of 335 node-negative breast cancer patients with a median follow-up of 152 months. The prognostic significance of IGKC for disease-free survival (DFS) and breast cancer-specific overall survival (OS) was evaluated with Kaplan-Meier survival analysis as well as univariate and multivariate Cox analysis adjusted for age at diagnosis, pT stage, histological grade, estrogen receptor (ER) status, progesterone receptor (PR) status, Ki-67 and human epidermal growth factor receptor 2 (HER-2) status.
  
  
  RESULTS
  160 patients (47.7%) showed strong expression of IGKC. Univariate analysis showed that IGKC was significantly associated with DFS (P = 0.017, hazard ratio [HR] = 0.570, 95% confidence interval [CI] = 0.360-0.903) and OS (P = 0.011, HR = 0.438, 95% CI = 0.233-0.822) in the entire cohort. The significance of IGKC was especially strong in ER negative and in luminal B carcinomas. In multivariate analysis IGKC retained its significance independent of established clinical factors for DFS (P = 0.004, HR = 0.504, 95% CI = 0.315-0.804) as well as for OS (P = 0.002, HR = 0.371, 95% CI = 0.196-0.705).
  
  
  CONCLUSIONS
  Expression of IGKC has an independent protective impact on DFS and OS in node-negative breast cancer.
authors.affiliation: Department of Obstetrics and Gynecology, Johannes Gutenberg University, Mainz, Germany.
authors.forename: Zonglin
authors.initials: Z
authors.lastname: Chen
authors.forename: Aslihan
authors.initials: A
authors.lastname: Gerhold-Ay
authors.forename: Susanne
authors.initials: S
authors.lastname: Gebhard
authors.forename: Daniel
authors.initials: D
authors.lastname: Boehm
authors.forename: Christine
authors.initials: C
authors.lastname: Solbach
authors.forename: Antje
authors.initials: A
authors.lastname: Lebrecht
authors.forename: Marco
authors.initials: M
authors.lastname: Battista
authors.forename: Isabel
authors.initials: I
authors.lastname: Sicking
authors.forename: Christina
authors.initials: C
authors.lastname: Cotarelo
authors.forename: Cristina
authors.initials: C
authors.lastname: Cadenas
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Marchan
authors.forename: Joanna D
authors.initials: JD
authors.lastname: Stewart
authors.forename: Mathias
authors.initials: M
authors.lastname: Gehrmann
authors.forename: Heinz
authors.initials: H
authors.lastname: Koelbl
authors.forename: Jan G
authors.initials: JG
authors.lastname: Hengstler
authors.forename: Marcus
authors.initials: M
authors.lastname: Schmidt
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000378:metabolism*; D007150:Immunohistochemistry; D008875:Middle Aged
chemical_list: D007145:Immunoglobulin kappa-Chains