title: Clinical significance of the frequency of regulatory T cells in regional lymph node lymphocytes as a prognostic factor for non-small-cell lung cancer.
abstract: BACKGROUND
  Regulatory T cells (Tregs) are potent immunosuppressive cells that play a crucial role in tumor immune escape. The purpose of the present study was to evaluate the prognostic significance of the frequency of CD4+CD25+Foxp3+ Tregs in the regional lymph node lymphocytes (RLNL) and peripheral blood lymphocytes (PBL) in patients who underwent surgical resection of non-small cell lung cancer (NSCLC).
  
  
  METHODS
  The RLNL and PBL in 158 NSCLC patients who underwent complete surgical resection were collected at the time of surgery. The proportions of CD4+CD25+Foxp3+ cells in the RLNL and PBL were determined by flow cytometry.
  
  
  RESULTS
  The average proportions of Tregs in the RLNL and PBL were 1.28% and 0.76%, respectively. The proportion of Tregs in the RLNL was significantly higher than that in the PBL (p < 0.0001). The 5-year overall survival rates of the patients according to the proportion of Tregs in the RLNL were 84.4% and 63.5% in the lower and higher groups, respectively. A significant difference was observed in the survival rate between the higher and lower groups (p = 0.0056). Among the patients with stage I disease, the 5-year survival rate (91.4%) was significantly higher in patients with the lower proportion of Tregs in RLNL that in the higher group (72.1%) (p = 0.0147).
  
  
  CONCLUSIONS
  The higher proportion of Tregs in the RLNL was a significant unfavorable prognostic factor, even in patients with node-negative NSCLC. The information about the proportion of Tregs in the RLNL might improve the discriminatory power for assessing the risk of the recurrence of NSCLC.
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan. Electronic address: hanagiri@med.uoeh-u.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hanagiri
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Shigematsu
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Shinohara
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Takenaka
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Sohich
authors.initials: S
authors.lastname: Oka
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Chikaishi
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Yoshika
authors.initials: Y
authors.lastname: Nagata
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Teruo
authors.initials: T
authors.lastname: Iwata
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Uramoto
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: So
authors.affiliation: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Tanaka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000276:immunology* / Q000401:mortality* / Q000473:pathology; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008175:Lung Neoplasms / Q000276:immunology* / Q000401:mortality* / Q000473:pathology; D008198:Lymph Nodes / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010641:Phenotype; D011379:Prognosis; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism; D055815:Young Adult
keywords: Foxp3; Immune escape mechanism; NSCLC; Regional lymph node lymphocytes; Regulatory T cells; Surgical resection