Interleukin-6 as a potential indicator for prevention of high-risk adenoma recurrence by dietary flavonols in the polyp prevention trial.
Serum interleukin-6 (IL-6), a proinflammatory cytokine, is considered an indicator of inflammation and may be an indicator of colorectal carcinogenesis given that inflammation can promote carcinogenesis. Flavonols, which can be found in fruits and vegetables, may inhibit colorectal carcinogenesis partly by inhibiting inflammation. We estimated odds ratios and 95% confidence intervals (95% CI) to determine whether serum IL-6 was associated with colorectal adenoma recurrence and flavonol intake and thus may serve as a risk indicator and as a response indicator to dietary flavonols. Serum IL-6 concentrations at baseline, year 1, and year 3 were measured in 872 participants from the intervention arm of the Polyp Prevention Trial, a 4-year trial that examined the effectiveness of a low-fat, high-fiber, high-fruit and vegetable diet on adenoma recurrence. Intake of flavonols, especially of isorhamnetin, kaempferol, and quercetin, was inversely associated with serum IL-6 concentrations (highest versus lowest flavonol intake quartile, 1.80 versus 2.20 pg/mL) and high-risk (OR, 0.51; 95% CI, 0.26-0.98) and advanced adenoma recurrence (OR, 0.17; 95% CI, 0.06-0.50). A decrease in IL-6 concentration during the trial was inversely associated with high-risk (OR, 0.44; 95% CI, 0.23-0.84) and advanced adenoma recurrence (OR, 0.47; 95% CI, 0.19-1.18). Individuals with above median flavonol intake and equal or below median IL-6 change after baseline had the lowest risk of recurrence of high-risk and advanced adenoma. Our results suggest that serum IL-6 may serve as a risk indicator and as a response indicator to dietary flavonols for colorectal cancer prevention.
Bobe
Gerd
G
Center for Cancer Research, National Cancer Institute, NIH, Department of Health and Human Services, Bethesda, Maryland, USA. gerd.bobe@oregonstate.edu
Albert
Paul S
PS
Sansbury
Leah B
LB
Lanza
Elaine
E
Schatzkin
Arthur
A
Colburn
Nancy H
NH
Cross
Amanda J
AJ
D000230:Adenocarcinoma / Q000517:prevention & control; D000236:Adenoma / Q000097:blood / Q000178:diet therapy / Q000517:prevention & control*; D018256:Adenomatous Polyps / Q000097:blood / Q000178:diet therapy / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D015415:Biomarkers; D003110:Colonic Neoplasms / Q000097:blood / Q000178:diet therapy / Q000517:prevention & control*; D003111:Colonic Polyps / Q000097:blood / Q000178:diet therapy / Q000517:prevention & control*; D015179:Colorectal Neoplasms / Q000517:prevention & control; D015930:Diet Records; D018752:Diet, Fat-Restricted; D004043:Dietary Fiber / Q000008:administration & dosage; D005260:Female; D044948:Flavonols / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D005500:Follow-Up Studies; D005638:Fruit; D006801:Humans; D007249:Inflammation / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D008517:Phytotherapy; D012306:Risk; D055502:Secondary Prevention; D014675:Vegetables
D016588:Anticarcinogenic Agents; D000975:Antioxidants; D015415:Biomarkers; D004043:Dietary Fiber; D044948:Flavonols; C508600:IL6 protein, human; D015850:Interleukin-6