title: High expression of nuclear Snail, but not cytoplasmic staining, predicts poor survival in nasopharyngeal carcinoma.
abstract: BACKGROUND
  Transcription factor Snail has been shown to promote tumor progression and metastasis in various cancers. However, its clinical significance in nasopharyngeal carcinoma (NPC) is still scanty. We have explored the clinical significance of Snail expression and its association with patient outcome in NPC.
  
  
  METHODS
  Immunohistochemistry was used to examine the expression levels of Snail in 122 patients with NPC.
  
  
  RESULTS
  Cytoplasmic Snail was detected in 37.7 %, and nuclear staining was detected in 49.2 % of primary tumors, respectively. No significant associations were found between cytoplasmic Snail and the clinicopathologic variables except lymph node metastasis (P = 0.042). However, nuclear Snail was significantly associated with tumor stage (P = 0.003), T classification (P = 0.045), lymph node metastasis (P = 0.019), distant metastasis (P = 0.003), and reduced E-cadherin expression (P = 0.021). Patients with high nuclear Snail expression, but not cytoplasmic staining, had significantly shorter survival than those with low expression (P < 0.001). Significantly, nuclear Snail was an independent prognostic predictor for NPC (P < 0.001). Furthermore, the prognostic impact was largely limited to stage III-IV patients.
  
  
  CONCLUSIONS
  We demonstrated first that nuclear Snail, but not cytoplasmic staining, predicts worse outcome. In addition, the prognostic value in stage III-IV suggests that nuclear Snail could be a potential therapeutic target for late stage of NPC patients.
authors.affiliation: Cancer Research Institute, Southern Medical University, 1838 Guangzhou Road North, Guangzhou, People's Republic of China.
authors.forename: Wei-Ren
authors.initials: WR
authors.lastname: Luo
authors.forename: Si-Yi
authors.initials: SY
authors.lastname: Li
authors.forename: Long-Mei
authors.initials: LM
authors.lastname: Cai
authors.forename: Kai-Tai
authors.initials: KT
authors.lastname: Yao
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D015820:Cadherins / Q000378:metabolism; D002277:Carcinoma / Q000378:metabolism* / Q000556:secondary; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism* / Q000473:pathology*; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D015820:Cadherins; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors