title: Expression and clinicopathologic significance of proteolysis-inducing factor in non-small-cell lung cancer: an immunohistochemical analysis.
abstract: BACKGROUND
  Proteolysis-inducing factor (PIF) is a 24-kD glycoprotein that has been identified in mice and in humans with cancer cachexia. The PIF is a putative mediator of cancer-associated weight loss, which induces atrophy of skeletal muscle.
  
  
  METHODS
  In this study, we detected the expression of the PIF in 71 patients with non-small-cell lung cancer (NSCLC) and 10 patients with healthy lung tissues as a control group using the immunohistochemical staining method. In addition, weight loss of patients and serum carcinoembryonic antigen (CEA) and cytokeratin fragment antigen 21-1 (CYFRA 21-1) were measured, and an analysis of overall survival was done.
  
  
  RESULTS
  Proteolysis-inducing factor was expressed in only 56.3% (40/71) of lung cancers and not in normal tissue. The positive rate of the PIF expression was significantly higher (P < .01) in patients with weight loss than in those without weight loss. There was no significant relationship (P > .05) between the PIF expression and the histology type, degree of differentiation, or tumor clinical stages in lung cancers. The sensitivity of the PIF was better than that of CEA (P < .05), but similar to that of CYFRA 21-1 in NSCLC.
  
  
  CONCLUSIONS
  Proteolysis-inducing factor expression was negatively related to the survival of patients with NSCLC in the medium to advanced stages (II-IV). There was a significant correlation between weight loss and survival in the PIF-positive patients.
authors.affiliation: Department of Thoracic Surgery, Shengjing Hospital, China Medical University, Shenyang, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Ji-Bin
authors.initials: JB
authors.lastname: Lu
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Hao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002100:Cachexia / Q000209:etiology; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008168:Lung / Q000737:chemistry; D008175:Lung Neoplasms / Q000150:complications / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011509:Proteoglycans / Q000032:analysis / Q000378:metabolism*; D012680:Sensitivity and Specificity; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D011509:Proteoglycans; C042057:proteolysis-inducing peptide