title: Serum levels of phytanic acid are associated with prostate cancer risk.
abstract: BACKGROUND
  Recent findings of over-expression of the AMACR gene in prostate cancer and association between sequence variants in the AMACR gene and prostate cancer risk, along with the well established findings of association between prostate cancer risk and over-consumption of dairy products and red meat, indirectly suggest that phytanic acid, which primarily comes from dietary intake of dairy and red meat and requires the AMACR enzyme for its metabolism, may be associated with prostate cancer risk. In this small case-control study, we assessed the association between phytanic acid levels and prostate cancer risk.
  
  
  METHODS
  One hundred and four prostate cancer patients and controls were recruited in North Carolina. Serum levels of phytanic acid were measured using a gas liquid chromatography/mass spectroscopy analysis, and a food frequency questionnaire was administered to each individual to assess dietary intake.
  
  
  RESULTS
  Three key findings are reported. First, there was a high correlation between two independent measurements of phytanic acid levels from the same individuals and the levels of phytanic acid were within the expected range, suggesting that serum levels of phytanic acid levels can be reliably measured in large epidemiological studies. Second, serum levels of phytanic acid among prostate cancer patients were significantly higher than that of unaffected controls, suggesting an association between phytanic acid and prostate cancer risk. Lastly, there was a significantly positive correlation between serum levels of phytanic acid and dietary intake of dairy and red meat servings during the year prior to the serum measurement.
  
  
  CONCLUSIONS
  Although the results from our study suggest phytanic acid levels may be associated with prostate cancer risk, they were based on a study with a small sample size. Much larger studies are required to confirm these important findings.
authors.affiliation: Center for Human Genomics, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA. jxu@wfubmc.edu
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Xu
authors.forename: Todd
authors.initials: T
authors.lastname: Thornburg
authors.forename: Aubrey R
authors.initials: AR
authors.lastname: Turner
authors.forename: Mara
authors.initials: M
authors.lastname: Vitolins
authors.forename: Doug
authors.initials: D
authors.lastname: Case
authors.forename: John
authors.initials: J
authors.lastname: Shadle
authors.forename: Lisa
authors.initials: L
authors.lastname: Hinson
authors.forename: Jielin
authors.initials: J
authors.lastname: Sun
authors.forename: Wennuan
authors.initials: W
authors.lastname: Liu
authors.forename: Baoli
authors.initials: B
authors.lastname: Chang
authors.forename: Tamara S
authors.initials: TS
authors.lastname: Adams
authors.forename: S Lilly
authors.initials: SL
authors.lastname: Zheng
authors.forename: Frank M
authors.initials: FM
authors.lastname: Torti
mesh_terms: D000368:Aged; D000818:Animals; D003611:Dairy Products; D004032:Diet; D015930:Diet Records; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D008460:Meat; D010831:Phytanic Acid / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood*; D012016:Reference Values; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000008:administration & dosage
chemical_list: D014807:Vitamin D; D010831:Phytanic Acid