title: Calcium affects biomarkers of colon carcinogenesis after right hemicolectomy.
abstract: BACKGROUND
  In Western societies colonic cancer most frequently develops in the distal colon, largely as a result of the composition of the diet. Modulation of dietary factors is therefore an attractive modality to reduce colorectal cancer risk. This study aims to evaluate the potentially protective effects of calcium in right hemicolectomy patients.
  
  
  METHODS
  A randomized controlled cross-over intervention trial was performed with 1000 mg of elemental calcium per day for 2 months in 15 right hemicolectomy patients. Primary endpoints were proliferative activity, determined by immunohistochemical detection of BrdU-labeled cells (LI) in rectal biopsies, and cytotoxicity and alkaline phosphatase activity of faecal water. Secondary endpoints were bile acid composition in faeces.
  
  
  RESULTS
  Calcium-reduced LI in the superficial one-third of the crypt (from 0.84 +/- 0.27% to 0.37 +/- 0.08%, P = 0.04) and a trend towards a lower total LI and LI in the mid one-third of the crypt was observed. Alkaline phosphatase activity was reduced from 6.2 +/- 2.6 U mL-1 in the placebo period to 4.6 +/- 2.2 in the calcium period (P = 0.02), and a trend toward a lower cytotoxicity of faecal water was observed. No effect on total bile acids in faeces was observed, but calcium increased the percentage of deoxycholic acid (from 49.6 +/- 7.0% to 56.5 +/- 6.2%, P = 0.03) and decreased the percentages of cholic acid (from 10.3 +/- 4.7% to 5.8 +/- 2.7%, P = 0.05) and lithocholic acid (from 26.7 +/- 3.4% to 23.9 +/- 2.9%, P = 0.04).
  
  
  CONCLUSIONS
  Calcium may have a protective effect against colorectal cancer risk in right hemicolectomy patients.
authors.affiliation: Department of Gastroenterology, Medical Oncology, University Hospital, Groningen, The Netherlands.
authors.forename: B A P
authors.initials: BA
authors.lastname: van Gorkom
authors.forename: R
authors.initials: R
authors.lastname: van der Meer
authors.forename: A
authors.initials: A
authors.lastname: Karrenbeld
authors.forename: T
authors.initials: T
authors.lastname: van der Sluis
authors.forename: N
authors.initials: N
authors.lastname: Zwart
authors.forename: D S M L
authors.initials: DS
authors.lastname: Termont
authors.forename: W
authors.initials: W
authors.lastname: Boersma-van Ek
authors.forename: E G E
authors.initials: EG
authors.lastname: de Vries
authors.forename: J H
authors.initials: JH
authors.lastname: Kleibeuker
mesh_terms: D000368:Aged; D000469:Alkaline Phosphatase / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis*; D002118:Calcium / Q000032:analysis / Q000627:therapeutic use*; D002455:Cell Division / Q000187:drug effects; D019826:Cholic Acid / Q000032:analysis; D003082:Colectomy; D003110:Colonic Neoplasms / Q000517:prevention & control* / Q000601:surgery; D018592:Cross-Over Studies; D003840:Deoxycholic Acid / Q000032:analysis; D004311:Double-Blind Method; D004847:Epithelial Cells / Q000187:drug effects; D005243:Feces / Q000737:chemistry; D005260:Female; D006801:Humans; D008095:Lithocholic Acid / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D011184:Postoperative Period
chemical_list: D014408:Biomarkers, Tumor; D003840:Deoxycholic Acid; D008095:Lithocholic Acid; D000469:Alkaline Phosphatase; D019826:Cholic Acid; D002118:Calcium