title: Vascularity of primary and metastatic renal cell carcinoma specimens.
abstract: OBJECTIVE
  Anti-angiogenic therapies are among the most commonly used drugs in renal cell carcinoma. Tumor vascularity, defined by microvessel area, may be associated with response to these drugs. Clinical studies suggest that metastatic sites are more responsive than primary tumors. Our purpose was to characterize microvessel area (MVA) in matched primary and metastatic samples and in samples of different histologies.
  
  
  METHODS
  We employed a method of automated, quantitative analysis of in situ tumor components to identify the area of CD-34 staining endothelial cells within renal cell carcinoma tumors. MVA was assessed in corresponding primary and metastatic samples from 34 patients, as well as in 334 primary nephrectomy specimens with variable histologies.
  
  
  RESULTS
  MVA measurements from different parts of the same tumor correlated well (R = 0.75), indicating that MVA was fairly uniform within a tumor. While MVA was slightly higher in primary tumors than corresponding metastatic sites, the difference was not statistically significant (P = 0.1). MVA in paired primary and metastatic samples correlated moderately well (R = 0.36). MVA was higher in clear cell than papillary histology and oncocytomas (P < 0.0001 and P = 0.018, respectively).
  
  
  CONCLUSIONS
  Lack of significant differences MVA in matched primary and metastatic samples suggests that both types of tumors should respond to anti-angiogenic drugs. This should be confirmed on additional cohorts. Given the small cohort, future predictive biomarker studies entailing MVA measurements should include specimens from both sites. Clear cell carcinomas are more vascular than other histologic subtypes, which may explain the higher response rates to anti-angiogenic therapies in clear cell tumors.
authors: Department of the School of Medicine, Yale University School of Medicine, New Haven, CT, USA.
authors: Saadia A
authors: SA
authors: Aziz
authors: Joshua
authors: J
authors: Sznol
authors: Adebowale
authors: A
authors: Adeniran
authors: John W
authors: JW
authors: Colberg
authors: Robert L
authors: RL
authors: Camp
authors: Harriet M
authors: HM
authors: Kluger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D002292:Carcinoma, Renal Cell / Q000098:blood supply* / Q000473:pathology / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007680:Kidney Neoplasms / Q000098:blood supply* / Q000473:pathology / Q000601:surgery; D008297:Male; D055806:Microvessels / Q000473:pathology; D008875:Middle Aged; D009362:Neoplasm Metastasis; D046888:Tissue Array Analysis