A Presurgical Study of Curcumin Combined with Anthocyanin Supplements in Patients with Colorectal Adenomatous Polyps.

Adenomatous polyps are precancerous lesions associated with a higher risk of colorectal cancer (CRC). Curcumin and anthocyanins have shown promising CRC-preventive activity in preclinical and epidemiological studies. The objective of this window-of-opportunity, proof-of principle trial was to evaluate the effect of curcumin combined with anthocyanin supplements on tissue biomarkers of colorectal adenomatous polyps. Eligible patients received either anthocyanin and curcumin supplementation or related matching placebo for 4-6 weeks before polyp removal. Adenomatous polyps and adjacent tissue biopsies were collected at baseline and after supplementation for immunohistochemical assessment of ß-catenin, NF-kappa B (NF-κB), Ki-67, P53, and dysplasia. No differences were observed in baseline biomarker expression between normal and dysplastic tissues. The combination of anthocyanins and curcumin resulted in a significant borderline reduction of NF-κB immunohistochemistry (IHC) expression in adenoma tissue (geometric mean ratio (GMR): 0.72; 95% confidence interval (CI): 0.51-1.00; p-value: 0.05) and a trend to a reduction of Ki-67 (GMR: 0.73; 95% CI: 0.50-1.08; p-value: 0.11). No significant modulation of biomarkers in normal adjacent mucosa was observed. We concluded that the combined supplementation of anthocyanins and curcumin seems to lead to a potentially favorable modulation of tissue biomarkers of inflammation and proliferation in colon adenomas.

Folic Acid Supplementation in Postpolypectomy Patients in a Randomized Controlled Trial Increases Tissue Folate Concentrations and Reduces Aberrant DNA Biomarkers in Colonic Tissues Adjacent to the Former Polyp Site.

BACKGROUND: Low folate status is associated with an increased risk of colorectal carcinogenesis. Optimal folate status may be genoprotective by preventing uracil misincorporation into DNA and DNA hypomethylation. Adenomatous polyps have low folate status compared with normal colonic mucosa, and they are surrounded by histologically normal mucosa that also is of low folate status. OBJECTIVE: In a randomized controlled trial conducted at a single Dublin hospital between April 2002 and March 2004, we assessed the effect of folic acid supplementation on tissue folate, uracil misincorporation into DNA, and global DNA hypomethylation in colonocytes isolated from sites of adenomatous polyps and from histologically normal tissue adjacent and 10-15 cm distal to them. METHODS: Twenty patients with adenomatous polyps on initial colonoscopy and polypectomy were randomly assigned to receive either 600 µg folic acid/d [n = 12, 38% men, mean age 64.3 y, and body mass index (BMI, in kg/m(2)) 26.6] or placebo (n = 8, 50% men, mean age 68.4 y, and BMI 27.2) for 6 mo, and then repeat the colonoscopy. Blood and colonocyte tissue folate concentrations were measured with the use of a microbiological assay. Uracil misincorporation and global DNA hypomethylation were measured in colonocytes with the use of modified comet assays. RESULTS: Over time, folic acid supplementation, compared with placebo, increased tissue folate (mean ± SEM) from 15.6 ± 2.62 pg/10(5) cells to 18.1 ± 2.12 pg/10(5) cells (P < 0.001) and decreased the global DNA hypomethylation ratio from 1.7 ± 0.1 to 1.0 ± 0.1 (P < 0.001). The uracil misincorporation ratio decreased by 0.5 ± 0.1 for the site adjacent to the polyp over time (P = 0.05). CONCLUSION: A response to folic acid supplementation, which increased colonocyte folate and improved folate-related DNA biomarkers of cancer risk, was seen in the participants studied. Exploratory analysis points toward the area formerly adjacent to polyps as possibly driving the response. That these areas persist after polypectomy in the absence of folate supplementation is consistent with a potentially carcinogenic field's causing the appearance of the polyp.

Serum selenium and colonic neoplastic risk.

BACKGROUND: Selenium deficiency has been associated with cancer risk in several organs. This association was investigated in neoplasia of the colorectum. DESIGN: A case-control study is reported with two patient series, colorectal cancer and colorectal adenomatous polyps, and a control group found to be free of colorectal neoplasia. Diagnosis was determined by colonoscopy and histologic review of suspected neoplasms. Serum drawn at the time of colonoscopy was subsequently assayed for selenium content, and quartiles based on selenium were defined. Crude and adjusted odds ratios with 95 percent confidence intervals for adenoma related to selenium were calculated, controlling for known or suspected risk factors including gender, age, race, body mass index, family history, tobacco use, alcohol consumption, serum beta carotene, serum alpha tocopherol, and serum ferritin. RESULTS: There were 138 controls who had no neoplastic disease, 139 adenoma patients, and 25 cancer patients. For adenoma, comparing higher quartiles of selenium to the first (lowest selenium), the adjusted odds ratio for the second quartile was 1.7 (95 percent confidence interval, 0.8-3.7), the third quartile was 1.4 (0.7-3.2), and the fourth (highest selenium) quartile was 1.8 (0.9-4). The odds ratios for cancer patients were 0.8 for the second quartile, 1 for the third quartile, and 1.7 for the fourth quartile. CONCLUSION: No trend could be detected toward a protective effect of higher levels of serum selenium for colonic benign or malignant tumors.