title: Caveolin-1 as a prognostic marker for local control after preoperative chemoradiation therapy in rectal cancer.
abstract: OBJECTIVE
  Caveolin-1 is a protein marker for caveolae organelles and has an essential impact on cellular signal transduction pathways (e.g., receptor tyrosine kinases, adhesion molecules, and G-protein-coupled receptors). In the present study, we investigated the expression of caveolin-1 in patients with rectal adenocarcinoma and correlated its expression pattern with the risk for disease recurrences after preoperative chemoradiation therapy (CRT) and surgical resection.
  
  
  METHODS
  Caveolin-1 mRNA and protein expression were evaluated by Affymetrix microarray analysis (n = 20) and immunohistochemistry (n = 44) on pretreatment biopsy samples of patients with locally advanced adenocarcinoma of the rectum, and were correlated with clinical and histopathologic characteristics as well as with 5-year rates of local failure and overall survival.
  
  
  RESULTS
  A significantly decreased median caveolin-1 intracellular mRNA level was observed in tumor biopsy samples as compared with noncancerous mucosa. Individual mRNA levels and immunohistologic staining, however, revealed an overexpression in 7 of 20 patients (35%) and 17 of 44 patients (38.6%), respectively. Based on immunohistochemical evaluation, local control rates at 5 years for patients with tumors showing low caveolin-1 expression were significantly better than for patients with high caveolin-1-expressing carcinoma cells (p = 0.05; 92%, 95% confidence interval [95% CI] = 82-102% vs. 72%, 95% CI = 49-84%). A low caveolin-1 protein expression was also significantly related to an increased overall survival rate (p = 0.05; 45%, 95% CI 16-60% vs. 82%, 95% CI = 67-97%).
  
  
  CONCLUSIONS
  Caveolin-1 may provide a novel prognostic marker for local control and survival after preoperative CRT and surgical resection in rectal cancer.
authors.affiliation: Department of Radiation Therapy and Oncology, University of Frankfurt am Main, Frankfurt am Main, Germany. franz.roedel@kgu.de
authors.forename: Franz
authors.initials: F
authors.lastname: Rödel
authors.forename: Gianni
authors.initials: G
authors.lastname: Capalbo
authors.forename: Claus
authors.initials: C
authors.lastname: Rödel
authors.forename: Christian
authors.initials: C
authors.lastname: Weiss
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D000069287:Capecitabine; D051242:Caveolin 1 / Q000032:analysis / Q000378:metabolism*; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D004334:Drug Administration Schedule; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000031:analogs & derivatives; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D009363:Neoplasm Proteins / Q000032:analysis / Q000378:metabolism*; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D011379:Prognosis; D040081:Protein Array Analysis / Q000379:methods; D012333:RNA, Messenger / Q000378:metabolism; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000401:mortality / Q000532:radiotherapy; D012074:Remission Induction
chemical_list: D051242:Caveolin 1; D009363:Neoplasm Proteins; D009944:Organoplatinum Compounds; D012333:RNA, Messenger; D000077150:Oxaliplatin; D003841:Deoxycytidine; D000069287:Capecitabine; D005472:Fluorouracil