Selenium

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Selenium

  1. 2. Serum Selenium Level and Prostate Cancer: A Case-Control Study G.POURMAND, M.D. Professor of Urology, Urology Research Center, Medical Sciences/University of Tehran Tehran, IRAN
  2. 3. Background  Essential trace element (1)  Meat, seafood, grains, eggs and etc (1)  Chemo-protective effects (2) 1- Combs GF Jr. 2004, Br J Cancer; Klein EA. 2004, J Urol; Platz EA and Helzlsouer KJ. 2001, Epidemiol Rev. 2- Redman C and Lee S. 1998, Cancer lett; Combs GF Jr. 2005, J Nutr; Kim YS and Milner J. 2001, Nutr Cancer.
  3. 4. <ul><ul><li>The anti-cancer activity </li></ul></ul><ul><ul><ul><ul><li>- Inhibiting cellular proliferation </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- Inducing apoptosis </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- Facilitating DNA repair by activation of p53 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- Disruption of androgen receptor signaling </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- Glutathione peroxidase </li></ul></ul></ul></ul><ul><ul><li>Redman et al. 1997, Carcinogenesis; Menter et al. 2000, Cancer Epidemiol Biomokers Prev; Seo et al. 2002, PNAS USA; Dong et al. 2003, Cancer Res. </li></ul></ul>
  4. 5.  Various parts of the world   Other studies  ≠ Other reports
  5. 6. Objective Does selenium have any effect on Prostate Cancer?
  6. 7. Materials and Methods <ul><li>• Prospective case-control study </li></ul><ul><ul><li>From November 2005 to December </li></ul></ul><ul><li>2006 </li></ul><ul><li>• Case group: 62 patients </li></ul><ul><ul><li>Control group: 68 consecutive </li></ul></ul><ul><li>participants </li></ul>
  7. 8. <ul><ul><li>Exclusion criteria: </li></ul></ul><ul><ul><ul><ul><li> Supplementary selenium consumption </li></ul></ul></ul></ul><ul><ul><ul><ul><li> Metabolic diseases </li></ul></ul></ul></ul><ul><ul><ul><ul><li> Immunodeficiency disorder </li></ul></ul></ul></ul><ul><ul><ul><ul><li> Previous intervention on prostate </li></ul></ul></ul></ul>
  8. 9. <ul><ul><li>Registered characteristics: </li></ul></ul><ul><ul><ul><ul><li>- Age </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- BMI </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- Smoking </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- FH of PCa </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- FFQ </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- PSA </li></ul></ul></ul></ul>
  9. 10. <ul><ul><li>Graphite furnace atomic absorption spectrometer </li></ul></ul><ul><ul><li>Statistical analysis: </li></ul></ul><ul><ul><ul><ul><li>- Categorical: Chi-square test or Fisher’s exact test </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- Continuous: independent samples t test </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- Association: Pearson’ s correlation </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- OR and 95% CI unconditional logistic regression model </li></ul></ul></ul></ul><ul><ul><ul><ul><li>- P<0.05 </li></ul></ul></ul></ul>
  10. 11. Result <ul><ul><li>130 participants (62 cases and 68 controls) </li></ul></ul>
  11. 12. Comparison of demographic and baseline characteristics of patients in both groups; (values are mean±SD)
  12. 13. Characteristic Cancer Group (n=62) Control Group (n=68) P value Age (yrs) 70.0±7.6 68.1±8.1 0.17 BMI (kg/m 2 ) 24.2±2.1 24.3±3.0 0.86 Se. Level (μg/L) 66.3±17.7 77.5±22.5 <0.002 FH of PCa 2(3.2%) 1(1.5%) 0.60 Smoking 0.46 Never 45(72.6%) 50(73.5%) Past 12(19.4%) 9(13.2%) Current 5(8.1%) 9(13.2%) PSA (ng/ml) 23.9±25.8 5.7±4.4 <0.001
  13. 14. Characteristic Cancer Group (n=62) Control Group (n=68) P value Tumor Grading - Low (GS<7) 17(27.4%) - Intermediate (GS=7) 22(35.5%) - High (GS>7) 23(37.1%) - Treatment procedure Surgery 24(38.7%) - Hormonal therapy 36(58.1%) - Radiotherapy 2(3.2%) - Nutritional selenium consumption 8.54±1.84 8.45±1.78 0.78
  14. 15. Association between age, BMI, smoking, serum selenium level and the risk of prostate cancer Variable OR 95%CI P value Age (yrs) 1.037 0.99-1.09 0.134 BMI (kg/m2) 1.000 0.87-1.15 0.999 Smoking habit Never 1 - - Former 0.935 0.34-2.26 0.896 Current 0.475 0.14-1.63 0.237 Selenium level (μg/L) <67.7 1 - - 67.7-89.29 0.478 0.21-1.10 0.084 ≥ 89.3 0.160 0.055-0.470 0.001
  15. 16. Correlation coefficients between serum selenium level and age, BMI, and PSA in controls group Variable Mean±SD Pearson r P value Age (yrs) 68.1±8.1 -0.19 0.12 BMI (kg/m 2 ) 24.3±3 -0.03 0.78 PSA (ng/ml) 5.75±4.4 0.03 0.83
  16. 18. Discussion <ul><ul><li>Possible inverse association between selenium and PCa </li></ul></ul><ul><ul><li>Agreement studies: </li></ul></ul><ul><ul><ul><ul><li>✓ Nutritional prevention of cancer (NPC) trial (1) </li></ul></ul></ul></ul><ul><ul><ul><ul><li>✓ Health professionals follow-up study (HPFS) (2) </li></ul></ul></ul></ul><ul><ul><ul><ul><li>✓ (Nomura et al. 2000, Cancer Epidemiol Biomarkers Prev) </li></ul></ul></ul></ul><ul><ul><ul><ul><li>✓ (Brooks et al. 2001, J Urol) </li></ul></ul></ul></ul><ul><ul><ul><ul><li>✓ (Vogt et al. 2003, Int J Cancer) </li></ul></ul></ul></ul><ul><ul><ul><ul><li>✓ (Van den Brandt. 2003, Cancer Epidemiol Biomarkers Prev) </li></ul></ul></ul></ul><ul><li>✓ (Li et al. 2004, J Natl cancer Inst) </li></ul><ul><li>✓ 2 recent meta analysis </li></ul><ul><li>1- Clark et al 1997, JAMA; Duffield-Lillico 2002, cancer Epidemiol Biomarkers Prev </li></ul><ul><li>2- Yoshizawa et al 1998, J Natl Cancer Inst </li></ul>
  17. 19. <ul><li>Disagreement studies: </li></ul><ul><ul><li>Carotene and Retinol Efficacy Trial (1) </li></ul></ul><ul><ul><li>(Lipsky et al. 2004, Urology) </li></ul></ul><ul><ul><li>(Allen et al. 2004, Br J Cancer) </li></ul></ul><ul><ul><li>(Peters et al. 2007, Am J Clin Nutr) </li></ul></ul><ul><li>1- Goodman et al. 2001, Cancer Epidemiol Biomarkers Prev </li></ul>
  18. 20.  SELECT Trial  Plasma selenium decreases by aging  Role in progression  Smoking and selenium-prostate cancer association
  19. 21. Conclusion  Our study supports the hypothesis that selenium may protect prostate cancer  Supplementary selenium  Selenium-rich foods
  20. 22. Thank you for your time and attention

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