title: Plasma carotenoids and tocopherols in relation to prostate-specific antigen (PSA) levels among men with biochemical recurrence of prostate cancer.
abstract: BACKGROUND
  Although men presenting with clinically localized prostate cancer (PrCA) often are treated with radical prostatectomy or radiation therapy with curative intent, about 25-40% develop biochemically recurrent PrCA within 5 years of treatment, which has no known cure. Studies suggest that carotenoid and tocopherol intake may be associated with PrCA risk and progression. We examined plasma carotenoid and tocopherol levels in relation to prostate-specific antigen (PSA) levels among men with PSA-defined biochemical recurrence of PrCA.
  
  
  METHODS
  Data analyzed were from a 6-month diet, physical activity and stress-reduction intervention trial conducted in South Carolina among biochemically recurrent PrCA patients (n=39). Plasma carotenoids and tocopherol levels were measured using high-performance liquid chromatography (HPLC). Linear regression was used to estimate least-square means comparing PSA levels of men with high versus low carotenoid/tocopherol levels, adjusting for covariates.
  
  
  RESULTS
  After adjusting for baseline PSA level, plasma cis-lutein/zeaxanthin level at 3 months was related inversely to PSA level at 3 months (P=0.0008), while α-tocopherol (P=0.01), β-cryptoxanthin (P=0.01), and all-trans-lycopene (P=0.004) levels at 3 months were related inversely to PSA levels at 6-months. Percent increase in α-tocopherol and trans-β-carotene levels from baseline to month 3 were associated with lower PSA levels at 3 and 6 months. Percent increase in β-cryptoxanthin, cis-lutein/zeaxanthin and all-trans-lycopene were associated with lower PSA levels at 6 months only.
  
  
  CONCLUSIONS
  Certain plasma carotenoids and tocopherols were related inversely to PSA levels at various timepoints, suggesting that greater intake of foods containing these micronutrients might be beneficial to men with PSA-defined PrCA recurrence.
authors.affiliation: Division of Epidemiology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, United States.
authors.forename: Samuel O
authors.initials: SO
authors.lastname: Antwi
authors.affiliation: Epidemiology and Biostatistics Arnold School of Public Health, 915 Greene St, Columbia, SC 29208, United States; Cancer Prevention and Control Program, Arnold School of Public Health, 915 Greene St, Columbia, SC 29208, United States. Electronic address: ssteck@sc.edu.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Steck
authors.affiliation: Epidemiology, Biostatistics, and Environmental Health, University of Memphis, 3825 Desoto Avenue, 224 Robison Hall, Memphis, TN 38152, United States.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Epidemiology, James Madison University, 800 Madison Drive, Harrisonburg, VA 22807, United States.
authors.forename: Lareissa
authors.initials: L
authors.lastname: Stumm
authors.affiliation: Epidemiology and Biostatistics Arnold School of Public Health, 915 Greene St, Columbia, SC 29208, United States.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Epidemiology and Biostatistics Arnold School of Public Health, 915 Greene St, Columbia, SC 29208, United States; Cancer Prevention and Control Program, Arnold School of Public Health, 915 Greene St, Columbia, SC 29208, United States.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Hurley
authors.affiliation: Epidemiology and Biostatistics Arnold School of Public Health, 915 Greene St, Columbia, SC 29208, United States; Cancer Prevention and Control Program, Arnold School of Public Health, 915 Greene St, Columbia, SC 29208, United States.
authors.forename: James R
authors.initials: JR
authors.lastname: Hebert
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000178:diet therapy / Q000534:rehabilitation; D000368:Aged; D002338:Carotenoids / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D004035:Diet Therapy / Q000379:methods; D018450:Disease Progression; D005081:Exercise Therapy / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D064866:Mindfulness / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000097:blood*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000178:diet therapy / Q000534:rehabilitation; D012307:Risk Factors; D024505:Tocopherols / Q000097:blood*
chemical_list: D002338:Carotenoids; D017430:Prostate-Specific Antigen; D024505:Tocopherols
keywords: Antioxidants; Biochemical recurrence; Carotenoids; Nutritional biomarkers; PSA; Prostate cancer; Tocopherols