title: Gender difference in the prognostic role of interleukin 6 in oral squamous cell carcinoma.
abstract: BACKGROUND
  Interleukin 6 (IL6) plays an important role in immunoregulation and tumorigenesis in human cancers. Oral squamous cell carcinoma (OSCC) is a malignant tumor of the oral cavity with a male predominant tendency and a poor clinical prognosis. Due to the relatively few cases in females, the gender difference of prognostic markers for OSCC is seldom discussed.
  
  
  METHODS
  In this study, we used immunohistochemical staining methods to investigate the associations between IL6 expression and the clinicopathological characteristics of OSCC. In addition, we collected 74 female and 263 male OSCC patients for evaluation.
  
  
  RESULTS
  High IL6 expression in tumor cells was significantly associated OSCC patient characteristics including female gender (P<0.001), high lymph node metastatic rate (P = 0.007), and poor tumor differentiation (P = 0.008). Tumor-expressed IL6 had prognostic role in male OSCC patients as defined by the log-rank test (P = 0.014), but not in female patients (P = 0.959). In male OSCC patients, high IL6 expression in tumor cells was associated with poor prognosis (P = 0.025) and a 1.454-fold higher death risk, as determined by Cox regression.
  
  
  CONCLUSIONS
  High IL6 expression in tumor cells was therefore significantly associated with aggressive clinical manifestations and might be an independent survival predictor, particularly in male OSCC patients.
authors.affiliation: Institute of Medicine, Chung Shan Medical University, Taichuang, Taiwan.
authors.forename: Chih-Jung
authors.initials: CJ
authors.lastname: Chen
authors.forename: Wen-Wei
authors.initials: WW
authors.lastname: Sung
authors.forename: Yueh-Min
authors.initials: YM
authors.lastname: Lin
authors.forename: Mu-Kuan
authors.initials: MK
authors.lastname: Chen
authors.forename: Ching-Hsiao
authors.initials: CH
authors.lastname: Lee
authors.forename: Huei
authors.initials: H
authors.lastname: Lee
authors.forename: Kun-Tu
authors.initials: KT
authors.lastname: Yeh
authors.forename: Jiunn-Liang
authors.initials: JL
authors.lastname: Ko
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000401:mortality*; D005260:Female; D015870:Gene Expression; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics* / Q000401:mortality*; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D012727:Sex Characteristics; D015996:Survival Rate
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6