title: Serum vitamin D, vitamin D binding protein, and lung cancer survival.
abstract: OBJECTIVE
  Vitamin D may prolong cancer survival by inhibiting tumor progression and metastasis, however, there are limited epidemiologic studies regarding the association between circulating 25-hydroxyvitamin D (25(OH)D) and lung cancer survival. The aim of this study was to examine the relationship between serum 25(OH)D and lung cancer specific survival and to evaluate whether vitamin D binding protein (DBP) concentration modified this association.
  
  
  METHODS
  25(OH)D and DBP were measured in fasting serum samples from 500 male lung cancer cases in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for lung cancer related death according to quartiles of season-specific 25(OH)D, DBP, and the molar ratio of 25(OH)D:DBP, a proxy for free circulating 25(OH)D.
  
  
  RESULTS
  Comparing highest to lowest quartiles, serum 25(OH)D (HR=1.18; 95% CI: 0.89-1.56) and DBP (HR=0.95; 95% CI: 0.71-1.26) were not associated with lung cancer survival and DBP concentration did not modify the association with 25(OH)D (p for interaction=0.56). There was suggestion of an association between higher serum 25(OH)D and better survival from adenocarcinoma (HR=0.64; 95% CI: 0.17-2.45) and small cell carcinoma (HR=0.55; 95% CI: 0.21-1.45), but these estimates were based on a relatively small number of cases.
  
  
  CONCLUSIONS
  Serum 25(OH)D was not associated with overall lung cancer survival regardless of DBP concentration, however, these findings should be examined in other studies that include women and subjects with higher 25(OH)D levels.
authors.affiliation: Cancer Prevention Fellowship Program, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD, United States; Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, United States. Electronic address: gabriella.anic@nih.gov.
authors.forename: Gabriella M
authors.initials: GM
authors.lastname: Anic
authors.affiliation: Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, United States.
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Weinstein
authors.affiliation: Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, United States.
authors.forename: Alison M
authors.initials: AM
authors.lastname: Mondul
authors.affiliation: Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Satu
authors.initials: S
authors.lastname: Männistö
authors.affiliation: Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, United States.
authors.forename: Demetrius
authors.initials: D
authors.lastname: Albanes
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000178:diet therapy / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D016019:Survival Analysis; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014809:Vitamin D-Binding Protein / Q000097:blood*; D024502:alpha-Tocopherol / Q000008:administration & dosage; D019207:beta Carotene / Q000008:administration & dosage
chemical_list: D014809:Vitamin D-Binding Protein; D019207:beta Carotene; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D024502:alpha-Tocopherol
keywords: 25-hydroxyvitamin D; Cohort; Lung cancer; Serum vitamin D; Survival; Vitamin D binding protein