title: Prediagnostic plasma pyridoxal 5'-phosphate (vitamin b6) levels and invasive breast carcinoma risk: the multiethnic cohort.
abstract: BACKGROUND
  Evidence from experimental and epidemiologic studies suggests that vitamin B6 may reduce the risk of breast cancer.
  
  
  METHODS
  We examined the association of prediagnostic plasma concentrations of pyridoxal-5'-phosphate (PLP), an active form of vitamin B6, with postmenopausal breast cancer risk in a case-control study nested in the multiethnic cohort in Hawaii and Southern California, including 706 cases and 706 controls matched on date of birth, ethnicity, study site, date of blood draw, time of blood draw, hours of fasting before blood draw, and use of menopausal hormones. OR and 95% confidence intervals (CI) were calculated using conditional logistic regression models.
  
  
  RESULTS
  Women with plasma PLP concentrations in the highest quartile had a 30% reduced risk of invasive breast cancer (CI: 0.50-0.98) as compared with the women in the lowest PLP quartile (P for trend = 0.02). The association seemed to be limited in cases with hormone receptor-positive tumors (P for heterogeneity = 0.04); and remained unchanged in the analysis restricted to women with blood samples collected more than one year before cancer diagnosis (OR = 0.69; CI: 0.48-0.99; P for trend = 0.03).
  
  
  CONCLUSIONS
  These data suggest that higher circulating levels of vitamin B6 are associated with a reduced risk of invasive postmenopausal breast cancer.
  
  
  CONCLUSIONS
  These results, in combination with information from two other prospective studies, suggest a role for vitamin B6 in the prevention of postmenopausal breast cancer. Additional studies are needed to further investigate potential heterogeneity of the vitamin B6 association with breast cancer risk by tumor hormone receptor status.
authors.affiliation: University of Hawaii Cancer Center, Honolulu, HI 96813, USA. glurie@cc.hawaii.edu
authors.forename: Galina
authors.initials: G
authors.lastname: Lurie
authors.forename: Lynne R
authors.initials: LR
authors.lastname: Wilkens
authors.forename: Yurii B
authors.initials: YB
authors.lastname: Shvetsov
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Ollberding
authors.forename: Adrian A
authors.initials: AA
authors.lastname: Franke
authors.forename: Brian E
authors.initials: BE
authors.lastname: Henderson
authors.forename: Laurence N
authors.initials: LN
authors.lastname: Kolonel
authors.forename: Marc T
authors.initials: MT
authors.lastname: Goodman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000097:blood* / Q000453:epidemiology / Q000208:ethnology / Q000473:pathology; D002140:California / Q000453:epidemiology; D016022:Case-Control Studies; D015331:Cohort Studies; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D006254:Hawaii / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D017698:Postmenopause / Q000097:blood; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D012307:Risk Factors; D025101:Vitamin B 6 / Q000097:blood*
chemical_list: D025101:Vitamin B 6