title: Expression of erythropoietin and its receptor in human renal cell carcinoma.
abstract: OBJECTIVE
  To investigate the prognostic impact of erythropoietin (EPO) and EPO-receptor (EPO-R) expression in tumour as well as serum EPO in patients with renal cell carcinoma (RCC).
  
  
  METHODS
  Using immunohistochemistry, EPO and EPO-R were assessed in tissue microarrays from 195 RCCs. RCC type, TNM stage, nuclear grade, survival, EPO and haemoglobin (Hb) levels in blood were registered.
  
  
  RESULTS
  Strong expression of EPO and EPO-R in tumour tissue was found in 83 and 56%, respectively. EPO and EPO-R expression differed between RCC types. Serum EPO and blood Hb did not correlate to the expression of EPO or EPO-R. A positive correlation was found between the expression of EPO and EPO-R (p = 0.028). Survival was not related to tumour EPO, whereas strong EPO-R expression indicated a non-significantly worse prognosis. Serum EPO correlated positively to TNM stage and nuclear grade and negatively to survival. A multivariate analysis showed that TNM stage and nuclear grade were independent prognostic factors. Tumour EPO and EPO-R expression as well as serum EPO added no independent prognostic information.
  
  
  CONCLUSIONS
  No correlation between EPO or EPO-R in tumour tissue and serum EPO or blood Hb was found. Neither EPO, EPO-R in tumour tissue nor serum EPO are independent prognostic factors.
authors.affiliation: Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Papworth
authors.forename: Anders
authors.initials: A
authors.lastname: Bergh
authors.forename: Kjell
authors.initials: K
authors.lastname: Grankvist
authors.forename: Börje
authors.initials: B
authors.lastname: Ljungberg
authors.forename: Torgny
authors.initials: T
authors.lastname: Rasmuson
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004921:Erythropoietin / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D017467:Receptors, Erythropoietin / Q000235:genetics / Q000378:metabolism*; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D006454:Hemoglobins; D017467:Receptors, Erythropoietin; D004921:Erythropoietin