title: The ratio of oleic-to-stearic acid in the prostate predicts biochemical failure after radical prostatectomy for localized prostate cancer.
abstract: OBJECTIVE
  To identify lifestyle related factors that may influence the prognosis of clinically localized prostate cancer we evaluated the relative impact of obesity and prostatic fatty acid concentrations at diagnosis on the risk of biochemical failure following radical prostatectomy.
  
  
  METHODS
  Height and weight were measured in 195 men scheduled for radical prostatectomy for clinically localized prostate cancer. Fatty acids were measured in nonmalignant prostate tissue collected at surgery. Biochemical failure was defined as detectable serum prostate specific antigen (0.1 ng/ml or greater). Cox proportional hazards models and logistic regression, respectively, were used to analyze the association of obesity (body mass index 30 kg/m2 or greater) and prostatic fatty acid concentrations with time to biochemical failure and the relative odds of biochemical failure at different time points after accounting for prostate specific antigen at diagnosis, surgical margin status, pathological stage, Gleason sum, patient age, race/ethnicity and other factors.
  
  
  RESULTS
  During an average followup of 56 months the oleic-to-stearic acid ratio predicted the risk of biochemical failure (multivariate HR 1.50, 95% CI 1.17-1.91, p = 0.001 per 1 standard deviation increase). Obesity did not correlate with biochemical failure during the entire study period. However, obesity tended to be associated with biochemical failure within the first 2 years (multivariate OR 2.55, 95% CI 0.84-7.77, p = 0.10).
  
  
  CONCLUSIONS
  The oleic-to-stearic acid ratio in the prostate predicts the risk of biochemical failure following radical prostatectomy for clinically localized prostate cancer. This observation and the tendency of obesity to be associated with biochemical failure during the first 2 years in our cohort suggest that lifestyle related factors influence the prognosis of clinically early stage prostate cancer.
authors.affiliation: Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Illinois 60612-4336, USA.
authors.forename: Jatupol
authors.initials: J
authors.lastname: Kositsawat
authors.forename: Robert C
authors.initials: RC
authors.lastname: Flanigan
authors.forename: Mohsen
authors.initials: M
authors.lastname: Meydani
authors.forename: Young-Ku
authors.initials: YK
authors.lastname: Choi
authors.forename: Vincent L
authors.initials: VL
authors.lastname: Freeman
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis; D015331:Cohort Studies; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000473:pathology*; D009367:Neoplasm Staging; D009765:Obesity / Q000150:complications; D019301:Oleic Acid / Q000032:analysis / Q000378:metabolism*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen; D011468:Prostatectomy / Q000009:adverse effects / Q000379:methods*; D011471:Prostatic Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013229:Stearic Acids / Q000032:analysis / Q000378:metabolism*; D016019:Survival Analysis
chemical_list: D015415:Biomarkers; D013229:Stearic Acids; D019301:Oleic Acid; C031183:stearic acid; D017430:Prostate-Specific Antigen