title: Vascular endothelial growth factor (VEGF) expression in locally advanced prostate cancer: secondary analysis of radiation therapy oncology group (RTOG) 8610.
abstract: BACKGROUND
  Angiogenesis is a key element in solid-tumor growth, invasion, and metastasis. VEGF is among the most potent angiogenic factor thus far detected. The aim of the present study is to explore the potential of VEGF (also known as VEGF-A) as a prognostic and predictive biomarker among men with locally advanced prostate cancer.
  
  
  METHODS
  The analysis was performed using patients enrolled on RTOG 8610, a phase III randomized control trial of radiation therapy alone (Arm 1) versus short-term neoadjuvant and concurrent androgen deprivation and radiation therapy (Arm 2) in men with locally advanced prostate carcinoma. Tissue samples were obtained from the RTOG tissue repository. Hematoxylin and eosin slides were reviewed, and paraffin blocks were immunohistochemically stained for VEGF expression and graded by Intensity score (0-3). Cox or Fine and Gray's proportional hazards models were used.
  
  
  RESULTS
  Sufficient pathologic material was available from 103 (23%) of the 456 analyzable patients enrolled in the RTOG 8610 study. There were no statistically significant differences in the pre-treatment characteristics between the patient groups with and without VEGF intensity data. Median follow-up for all surviving patients with VEGF intensity data is 12.2 years. Univariate and multivariate analyses demonstrated no statistically significant correlation between the intensity of VEGF expression and overall survival, distant metastasis, local progression, disease-free survival, or biochemical failure. VEGF expression was also not statistically significantly associated with any of the endpoints when analyzed by treatment arm.
  
  
  CONCLUSIONS
  This study revealed no statistically significant prognostic or predictive value of VEGF expression for locally advanced prostate cancer. This analysis is among one of the largest sample bases with long-term follow-up in a well-characterized patient population. There is an urgent need to establish multidisciplinary initiatives for coordinating further research in the area of human prostate cancer biomarkers.
authors.affiliation: Department of Radiation Oncology, Prince Edward Island Cancer Treatment Centre, Charlottetown, PEI, Canada. Pan.Larry@gmail.com
authors.forename: Larry
authors.initials: L
authors.lastname: Pan
authors.forename: Seunghee
authors.initials: S
authors.lastname: Baek
authors.forename: Pamela R
authors.initials: PR
authors.lastname: Edmonds
authors.forename: Mack
authors.initials: M
authors.lastname: Roach
authors.forename: Harvey
authors.initials: H
authors.lastname: Wolkov
authors.forename: Satish
authors.initials: S
authors.lastname: Shah
authors.forename: Alan
authors.initials: A
authors.lastname: Pollack
authors.forename: M Elizabeth
authors.initials: ME
authors.lastname: Hammond
authors.forename: Adam P
authors.initials: AP
authors.lastname: Dicker
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000008:administration & dosage; D014408:Biomarkers, Tumor / Q000032:analysis*; D059248:Chemoradiotherapy; D017326:Clinical Trials, Phase III as Topic; D018572:Disease-Free Survival; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000628:therapy; D016032:Randomized Controlled Trials as Topic; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis / Q000096:biosynthesis*
chemical_list: D000726:Androgen Antagonists; D014408:Biomarkers, Tumor; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A