title: Prediagnostic plasma vitamin B6 (pyridoxal 5'-phosphate) and survival in patients with colorectal cancer.
abstract: OBJECTIVE
  Higher plasma pyridoxal 5'-phosphate (PLP) levels are associated with a decreased incidence of colorectal cancer, but the influence of plasma PLP on survival of patients with colorectal cancer is unknown. We prospectively examined whether prediagnostic plasma PLP levels are associated with mortality among colorectal cancer patients.
  
  
  METHODS
  We included 472 incident cases of colorectal cancer identified in the Nurses' Health Study, the Health Professionals Follow-up Study, and the Physicians' Health Study from 1984 to 2002. The patients provided blood samples two or more years before cancer diagnosis. Stratified Cox proportional hazards models were used to calculate hazard ratios (HR) with 95 % confidence intervals (CI) adjusted for other risk factors for cancer survival.
  
  
  RESULTS
  Higher plasma PLP levels were not associated with a significant reduction in colorectal cancer-specific (169 deaths) or overall mortality (259 deaths). Compared with patients who had less than 45 pmol/ml of plasma PLP (median: 33.6 pmol/ml), those who had 110 pmol/ml or higher levels (median: 158.8 pmol/ml) had multivariable HRs of 0.85 (95 % CI 0.50-1.45, p trend = 0.37) and 0.87 (95 % CI 0.56-1.35, p trend = 0.24) for colorectal cancer-specific and overall mortality. Higher plasma PLP levels, however, seemed to be associated with better survival among patients who had lower circulating 25-hydroxyvitamin D3 levels (<26.5 ng/ml) (p interaction ≤.005).
  
  
  CONCLUSIONS
  Higher prediagnostic plasma PLP levels were not associated with an improvement on colorectal cancer survival overall. Further research is needed to clarify the influence of vitamin B6 on colorectal cancer progression and survival.
authors: Department of Food and Nutrition, Kyung Hee University, Seoul, Korea. youjinje@khu.ac.kr
authors: Youjin
authors: Y
authors: Je
authors: Jung Eun
authors: JE
authors: Lee
authors: Jing
authors: J
authors: Ma
authors: Xuehong
authors: X
authors: Zhang
authors: Eunyoung
authors: E
authors: Cho
authors: Bernard
authors: B
authors: Rosner
authors: Jacob
authors: J
authors: Selhub
authors: Charles S
authors: CS
authors: Fuchs
authors: Jeffrey
authors: J
authors: Meyerhardt
authors: Edward
authors: E
authors: Giovannucci
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006282:Health Personnel; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate; D025101:Vitamin B 6 / Q000097:blood*; D014803:Vitamin B Complex / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; D014803:Vitamin B Complex; D025101:Vitamin B 6