Supplementation with phytoestrogens and insoluble fibers reduces intestinal carcinogenesis and restores ER-ß expression in Apc-driven colorectal carcinogenesis.

Supplementation with phytoestrogens and insoluble fibers has been reported to reduce duodenal polyps in colectomized familial adenomatous polyposis patients, with a mechanism involving, at least in part, upregulation of estrogen receptor-ß subtype, whose expression is lowered during intestinal tumorigenesis. These data suggest a protective effect also in the colon, the main target organ for tumorigenesis in familial adenomatous polyposis and a major cancer type in non-familial (sporadic) cancers. Therefore, we tested whether a similar preparation might reduce tumorigenesis in the colon of Pirc rats (F344/NTac-Apc) mutated in the Apc gene and thus, like familial adenomatous polyposis patients, spontaneously developing multiple tumors in the colon. We first demonstrate that estrogen receptor-ß expression in Pirc rat colon is significantly down-regulated compared to age-matched wt rats. Then, Pirc rats aged 1 month were treated for 3 months with Adipol (Adi), a patented preparation containing phytoestrogens and insoluble fibers. Colon tumorigenesis was significantly reduced by Adi treatment (colon tumors/rat were 5.3 ± 0.8 and 2.9 ± 0.3, Mucin Depleted Foci/rat 127 ± 6.6 and 97.1 ± 8.6 in Controls and Adi-treated rats, respectively, means ± SE, P < 0.01). The treatment also normalized colon proliferation pattern along the crypt and significantly increased apoptosis in colon tumors. Estrogen receptor-ß expression was increased by Adi treatment, especially in the tumors. These positive effects suggest that Adipol may be exploited as a chemopreventive agent to reduce cancer risk in familial adenomatous polyposis patients and to postpone prophylactic colectomy. Moreover, given the similarities between familial adenomatous polyposis and sporadic colorectal cancer, it might also be used as chemopreventive agent in colorectal cancer patients at risk.

Can supplementation of phytoestrogens/insoluble fibers help the management of duodenal polyps in familial adenomatous polyposis?

Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disorder, and prophylactic colectomy has been shown to decrease the incidence of colorectal cancer (CRC). Duodenal cancer and desmoids are now the leading causes of death in FAP. We evaluate whether 3 months of oral supplementation with a patented blend of phytoestrogens and indigestible insoluble fibers (ADI) help the management of FAP patients with ileal pouch-anal anastomosis (IPAA). In a prospective open label study, we enrolled 15 FAP patients with IPAA and duodenal polyps who underwent upper gastrointestinal endoscopy at baseline and after 3 months of treatment. The primary endpoint was the change in gene expression in polyp mucosa, whereas the secondary endpoint was the reduction in polyp number and size. After 3 months of ADI treatment, all patients showed a reduction in the number and size of duodenal polyps (P = 0.021). Analysis of the expression of CRC promoting/inhibiting genes in duodenal polyps biopsies demonstrated that different CRC-promoting genes (PCNA, MUC1 and COX-2) were significantly downregulated, whereas CRC-inhibiting genes (ER-ß and MUC2) were significantly upregulated after ADI treatment. In conclusion, ADI proved to be safe and effective, and its long-term effects on FAP patients need further investigation. Judging from the results we observed on COX-2 and miR-101 expression, the short-term effects of ADI treatment could be comparable with those obtained using COX-2 inhibitors, with the advantage of being much more tolerable in chronic therapies and void of adverse events.

Eviendep® reduces number and size of duodenal polyps in familial adenomatous polyposis patients with ileal pouch-anal anastomosis.

AIM: To evaluate if 3 mo oral supplementation with Eviendep® was able to reduce the number of duodenal polyps in familial adenomatous polyposis (FAP) patients with ileal pouch-anal anastomosis (IPAA). METHODS: Eleven FAP patients with IPAA and duodenal polyps were enrolled. They underwent upper gastrointestinal (GI) endoscopy at the baseline and after 3 mo of treatment. Each patient received 5 mg Eviendep twice a day, at breakfast and dinner time, for 3 mo. Two endoscopists evaluated in a blinded manner the number and size of duodenal polyps. Upper GI endoscopies with biopsies were performed at the baseline (T0) with the assessment of the Spigelman score. Polyps > 10 mm were removed during endoscopy and at the end of the procedure a new Spigelman score was determined (T1). The procedure was repeated 3 mo after the baseline (T2). Four photograms were examined for each patient, at T1 and T2. The examined area was divided into 3 segments: duodenal bulb, second and third portion duodenum. Biopsy specimens were taken from all polyps > 10 mm and from all suspicious ones, defined by the presence of a central depression, irregular surface, or irregular vascular pattern. Histology was classified according to the updated Vienna criteria. RESULTS: At baseline the mean number of duodenal detected polyps was 27.7 and mean sizes were 15.8 mm; the mean Spigelman score was 7.1. After polypectomy the mean number of duodenal detected polyps was 25.7 and mean sizes were 7.6 mm; the mean Spigelman score was 6.4. After 3 mo of Eviendep bid, all patients showed a reduction of number and size of duodenal polyps. The mean number of duodenal polyps was 8 (P = 0.021) and mean size was 4.4 mm; the mean Spigelman score was 6.6. Interrater agreement was measured. Lesions > 1 cm found a very good degree of concordance (kappa 0.851) and a good concordance was as well encountered for smaller lesions (kappa 0.641). CONCLUSION: Our study demonstrated that short-term (90 d) supplementation with Eviendep® in FAP patients with IPAA and with recurrent adenomas in the duodenal mucosa, resulted effective in reducing polyps number of 32% and size of 51%.

Wheat bran fiber and development of adenomatous polyps: evidence from randomized, controlled clinical trials.

Mutations in oncogenes and tumor suppressor genes are thought to initiate and promote the pathway to colorectal cancer, leading to hyperproliferation, the development of adenomas, and progression to gross malignancy. Intervention at any of these steps can potentially prevent the development of cancer. Several randomized, controlled trials have investigated the effect of dietary interventions, including the addition of wheat bran fiber, on the development of adenomatous polyps. In a familial adenomatous polyposis trial, patients were treated with 4 g of ascorbic acid plus 400 mg of alpha-tocopherol per day alone or with a grain fiber supplement (22.5 g/day) over a 4-year period. On an actual-intake basis, the combined intervention inhibited the development of rectal polyps. However, the Toronto Polyp Prevention Trial found no significant differences in polyp recurrence rates between patients who were counseled to follow a low-fat, high-fiber diet and patients consuming a typical Western diet with placebo fiber. A 9-month study of patients with resected colon adenomas found that dietary wheat bran fiber significantly reduced total, primary, and secondary fecal bile acid concentrations and excretion rates. Such bile acid levels are thought to be related to the risk of developing cancer. The Australian Polyp Prevention Project reported that the combination of fat reduction and a supplement of wheat bran reduced the incidence of large colorectal adenomas. These latter results suggest that intervention with a low-fat wheat bran supplemented diet inhibits the transition from smaller to larger adenomas, which may be a critical step in determining which adenomas progress to malignancy.

A generalized estimating equations approach for testing ordered group effects with repeated measurements.

In repeated measures studies, we are often interested in comparing group effects in which groups are associated with a certain order relation. We propose testing procedures for ordered group effects using the generalized estimating equations (GEE) approach of Liang and Zeger (1986, Biometrika 73, 13-22). The order-constrained GEE estimators of group effects are approximated by the isotonic regression of the unconstrained GEE estimators. Based on these constrained estimators, we construct test statistics for detecting ordered group effects. The limiting distributions of the test statistics are mixtures of chi-square distributions. A Monte Carlo experiment shows improved performances of the proposed tests over the usual chi-square tests in detecting ordered group effects. The proposed test procedures are illustrated by familial polyposis supplementation trial data.

Randomized, double-blinded, placebo-controlled study of effect of wheat bran fiber and calcium on fecal bile acids in patients with resected adenomatous colon polyps.

BACKGROUND: Ongoing epidemiologic and nutritional studies suggest that colorectal carcinogenesis is consistent with complex interactions between genetic susceptibility and environmental and dietary factors. Among the dietary components found to reduce colon cancer risk are high intakes of dietary fiber and calcium. PURPOSE: We designed and conducted a randomized, double-blinded, placebo-controlled trial involving supplementation of the customary dietary intake with fiber and calcium and measurements of fecal bile acids to examine the potential mechanisms by which added dietary interventions might reduce colorectal cancer risk. METHODS: In a randomized, double-blinded, phase II study, we used a factorial design to measure the effects of dietary wheat bran fiber (2.0 or 13.5 g/day) in the form of cereal and supplemental calcium carbonate (250 or 1500 mg/day elemental calcium) taken as a tablet on fecal bile acid concentrations and excretion rates. Measurements were made at base-line randomization (i.e., after a 3-month placebo run-in period using 2.0 g wheat bran fiber plus 250 mg calcium carbonate) and after 3 and 9 months on treatment in a randomly selected 52-patient subsample of the 95 fully assessable study participants who had a history of colon adenoma resection. Concentrations of fecal bile acids, total, primary (i.e., chenodeoxycholic and cholic), and secondary (i.e., deoxycholic, lithocholic, and ursodeoxycholic), were measured in 72-hour stool samples by gas-liquid chromatography. All P values resulted from two-sided tests. RESULTS: All geometric mean fecal bile acid concentrations and excretion rates were lower at 9 months than at 0 months or 3 months on treatment in the high-dose fiber, high-dose calcium, and high-dose fiber/high-dose calcium treatment groups. The high-dose fiber effect at 9 months of supplementation was statistically significant with respect to virtually all geometric mean fecal bile acid concentrations and excretion rates. For example at 9 months versus 0 months, high-dose fiber supplementation caused a reduction in fecal concentrations of total bile acids (52% reduction; P = .001) and deoxycholic acid (48% reduction; P = .003). High-dose calcium supplementation also had a significant, but lower, effect at 9 months versus 0 months on the geometric mean total bile acid (35% reduction; P = .044) and deoxycholic fecal bile acid (36% reduction; P = .052) concentrations. CONCLUSIONS: High-dose wheat bran fiber and calcium carbonate supplements given for 9 months are associated with statistically significant reductions in both total and secondary fecal bile acid concentrations and excretion rates in patients with resected colon adenomas. This study supports the hypothesis that one of the important ways in which a high intake of wheat bran fiber and calcium may reduce the risk of colorectal neoplasia and cancer is by reduction of the concentrations of fecal bile acids. IMPLICATION: Phase III studies of these agents in the prevention of adenoma recurrence are necessary to confirm this hypothesis and have now been initiated at multiple institutions.

Effects of different doses of fish oil on rectal cell proliferation in patients with sporadic colonic adenomas.

BACKGROUND/AIMS: Fish oil supplementation can reduce cytokinetic anomalies in the flat rectal mucosa of patients with sporadic colorectal adenoma. This study attempted to identify an optimum dose for fish oil supplementation and evaluate the persistence of its effects during long-term administration. METHODS: In a double-blind study, 60 patients with sporadic adenomas received 2.5, 5.1, or 7.7 g of fish oil per day or placebo for 30 days. [3H]thymidine autoradiographic labeling indices were calculated in flat rectal mucosal biopsy specimens collected before and after supplementation. In a subsequent study, 15 patients with polyps received 2.5 g of fish oil per day. Proliferative parameters, mucosal fatty acids, and mucosal and plasma alpha-tocopherol levels were evaluated before, during, and after 6 months of supplementation. RESULTS: Mean proliferative indices and mucosal arachidonic acid levels decreased significantly (and to similar degrees) in all treated groups, whereas mucosal eicosapentaenoic and docosahexaenoic acid levels increased. Significantly reduced proliferation was observed only in patients with abnormal baseline patterns. These effects persisted during long-term, low-dose treatment. A transient reduction in mucosal (but not plasma) alpha-tocopherol levels was observed after 1 month of treatment. Side effects were insignificant. CONCLUSIONS: Low-dose fish oil supplementation has short-term and long-term normalizing effects on the abnormal rectal proliferation patterns associated with increased colon cancer risk.