title: Relationships between the effect of sunitinib and immature blood vessels in metastatic renal cell cancer.
abstract: BACKGROUND
  This study was conducted to investigate the relationships between the effect of sunitinib and immature microvessels which are not covered by pericytes.
  
  
  METHODS
  This study involved 29 patients with clear-cell renal cell carcinoma (RCC) who took sunitinib after radical nephrectomy or biopsy due to metastatic RCC. Associations among clinicopathological factors, responses to sunitinib, and patient survival were reviewed. CD31 was used to stain endothelial cells, and anti-α-smooth muscle actin was used to stain pericytes. Immature vessels were defined as vessels that were positive only for CD31 staining. A high pericyte coverage was defined as a rate of pericyte coverage above 40%.
  
  
  RESULTS
  Partial responses, disease stabilization, and disease progression constituted 51.7, 10.4, and 37.9% of cases, respectively. Nine cases had a low pericyte coverage (31.0%). In the high-pericyte-coverage group, the number of metastatic sites was smaller (p=0.003). The overall response rate to sunitinib was greater in the high-pericyte-coverage group than in the low-pericyte-coverage group (p=0.027). The median overall survival and the median progression-free survival were not significantly different between the high- and low-pericyte-coverage groups.
  
  
  CONCLUSIONS
  In the high-pericyte-coverage group, the overall response rates to sunitinib were higher, and the numbers of metastatic sites were smaller.
authors.affiliation: Department of Urology, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Byung Hoon
authors.initials: BH
authors.lastname: Kim
authors.forename: Jee Chul
authors.initials: JC
authors.lastname: Sohn
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Ha
authors.forename: Choal Hee
authors.initials: CH
authors.lastname: Park
authors.forename: Mi Sun
authors.initials: MS
authors.lastname: Choe
authors.forename: Hye Ra
authors.initials: HR
authors.lastname: Jung
authors.forename: Chun Il
authors.initials: CI
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D001808:Blood Vessels / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D002292:Carcinoma, Renal Cell / Q000098:blood supply* / Q000188:drug therapy* / Q000401:mortality / Q000556:secondary; D017024:Chemotherapy, Adjuvant; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007211:Indoles / Q000627:therapeutic use*; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000098:blood supply* / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic; D009392:Nephrectomy; D020286:Pericytes / Q000473:pathology; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D016016:Proportional Hazards Models; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011758:Pyrroles / Q000627:therapeutic use*; D000077210:Sunitinib; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D020533:Angiogenesis Inhibitors; D007211:Indoles; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D000077210:Sunitinib