The effect of wheat bran fiber and calcium supplementation on rectal mucosal proliferation rates in patients with resected adenomatous colorectal polyps.

Colorectal cancers continue as the second most common cause of death from cancer in the United States. Only a few prospective, randomized clinical trials have been performed to evaluate the potential preventive effects of dietary fiber or calcium in patients with an increased risk for the development or recurrence of colorectal cancer. We designed and conducted a double-blinded, placebo-controlled randomized trial involving supplementation of fiber and calcium intake and measurements of [3H]thymidine labeling index (LI) percentages in rectal mucosal biopsies obtained from patients with resected colorectal adenomas to examine the potential mechanisms by which dietary interventions might reduce colorectal cancer risk. We performed a randomized, double-blinded, Phase II study, using a factorial design to measure the effects of supplemental dietary wheat bran fiber (2.0 or 13.5 g/day) and calcium carbonate (250 or 1500 mg/day elemental calcium) supplementation on [3H]thymidine LI percentages in rectal mucosal crypts and 24-h in vitro outgrowth cultures. Measurements were made at baseline randomization (i.e., after a 3-month placebo run-in period using 2.0 g of wheat bran fiber plus 250 mg of calcium carbonate) and after 3 and 9 months on treatment in 100 randomized participants who had a history of colon adenoma resection. Neither the wheat bran fiber nor the calcium carbonate supplements significantly reduced [3H]thymidine LI percentages in rectal mucosal crypts (total or compartmental analysis) or 24-h in vitro outgrowth cultures at either 3 or 9 months of daily supplementation in the 93 evaluable participants. We conclude that 9 months of high-dose wheat bran fiber and calcium carbonate supplementation in study participants with a history of recently resected colorectal adenomas does not have a significant effect on cellular proliferation rates in rectal mucosal biopsies, comparing 3- and 9-month results to baseline results. Ultimately, there is great need for the evaluation of these two different nutrient interventions in the setting of Phase III studies wherein adenomatous polyp recurrence, rather than a rectal mucosal biomarker, serves as the primary end point.

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.

A prospective comparison of anoscopy and fiberendoscopy in detecting anal lesions.

With the increase in rectal and perianal disease, thorough examination of this area is necessary in every patient with colorectal complaints. We compared the current fibersigmoidoscope and colonoscope with routine anoscopy in the detection rate of perianal pathology in 115 consecutive patients. Straight withdrawal and retroflexion in the rectum of the fiberoptic instruments led to lesion detection rates of 78% and 54%, respectively. The anoscope showed 99% of lesions. Anoscopy was easily learned and required less than a minute to perform. We conclude that anoscopy should be performed in every patient undergoing fibersigmoidoscopy or colonoscopy. Instructions in this procedure should be provided in all training programs.

Esophageal strictures following endoscopic variceal sclerotherapy: clinical course and response to dilation therapy.

The authors evaluated the clinical course and management of 10 sclerotherapy patients with obliterated varices and symptomatic esophageal strictures. Strictures developed after 29 injections of 51 ml of sodium tetradecyl sulfate on an average of three sessions. Although the severity of dysphagia was variable, all patients were successfully managed with bougienage. To evaluate risk factors related to stricture formation a comparison was made with 14 nonstricture patients with obliterated varices. Multiple parameters of sclerotherapy were evaluated including total volume of sclerosant, number of injections, number of EVS sessions, volume of sclerosant, number of injections per session, number of esophageal ulcerations, and frequency of EVS treatments. No aspects of therapy clearly predicted the development of esophageal stricture.

The long and short of flexible sigmoidoscopy: does it matter?

Physicians performing fiberoptic sigmoidoscopy may choose between a 35 and 60 cm instrument. Confusion and dispute exist concerning the advantages of one over the other. In an effort to resolve this question, 100 consecutive symptomatic patients were examined in an outpatient sigmoidoscopy clinic. Both the Olympus OSF-30 and Olympus OSF-60 flexible sigmoidoscopes were used on each patient alternately. Mean examination time, patient tolerance, diagnostic findings, instrument cost, physician training time, and insertion length were recorded and compared. The longer scope detected five more polyps and 25 additional cases of diverticulosis which were located beyond the reach of the shorter scope. The increased number of findings with the longer scope was expected; however, the increased number of polyps was not statistically significant. The additional number of findings with the longer scope was expected and with increased number of examinations the increased number of polyps may prove to be statistically significant. Neither instrument can substitute for colonoscopy in the overall management of colorectal neoplasms. We conclude that with adequate training and cost control, either instrument can be used for screening proctosigmoidoscopy; but the trend suggests a greater number of polyps are detected with the longer instrument.

Percutaneous endoscopic gastrostomy (PEG). A new procedure comes of age.

Our cumulative literature review suggests PEG is a simple, relatively safe, and cost-effective means of establishing enteral access for patients who qualify for long-term nutritional support. Tube placement can be achieved in 98% of patients, usually within 15 to 30 minutes without general anesthesia. The gastrostomy catheter can be easily removed when treatment is ended and conveniently replaced if accidentally dislodged. Complications occur in approximately 17% of patients, but only 3.0% are regarded as serious. No procedure-related deaths have been reported. PEG as the initial choice for feeding tube placement followed by surgical gastrostomy in patients in whom PEG is unsuccessful is a reasonable approach to nutritional management in appropriate patients. PEG for purposes of chronic gastrointestinal decompression and internalization of biliary drainage holds promise but requires further evaluation.