Antioxidant supplement and long-term reduction of recurrent adenomas of the large bowel. A double-blind randomized trial.

BACKGROUND: Patients who undergo polypectomy are at increased risk of adenoma recurrence. The preventive potential of vitamins (A, C and E) and selenium supplementation represent an interesting opportunity for colorectal cancer prevention. METHODS: To assess the efficacy of a combination of these micronutrients in reducing the incidence of recurrent adenomas in subjects on post-polypectomy endoscopic follow-up, a double-blind placebo-controlled randomized trial was started in Italy in 1988. A total of 411 patients were randomized to receive either an active compound (200 µg selenium, 30 mg zinc, 2 mg vitamin A, 180 mg vitamin C, 30 mg vitamin E) or a placebo daily for 5 years. Of them, 330 had follow-up colonoscopy (164 in the intervention and 166 in the placebo group). RESULTS: After a median follow-up of 4 years (range 1-15 years), 100 patients had recurrence: 38 in the intervention and 62 in the placebo arm. The 15-year cumulative incidence of recurrence was 48.3% in the intervention and 64.5% in the placebo arm (HR = 0.59; log-rank P = 0.009). A 39% reduction of the risk of recurrence was observed in the intervention compared to the placebo group (adjusted HR = 0.61; 95% CI 0.41-0.92): the risk reduction was similar for small tubular (adjusted HR = 0.61; 95% CI 0.37-0.99) and advanced adenomas (adjusted HR = 0.50; 95% CI 0.24-1.01). CONCLUSIONS: Our study showed a statistically significant effect of antioxidant supplementation on adenoma recurrence. Further clinical trials are needed to address the role of antioxidants in subgroups of subjects at increased risk for colorectal cancer.

Enfoque actual para el manejo de los pólipos colorrectales / Updating outline for the management of colorectal polyps

La interrupción de la secuencia adenoma-displasia-carcinoma, sin lugar a dudas, va a dar lugar a una reducción en la mortalidad por cáncer colorrectal. Es por ésto que el diagnóstico y extirpación de los pólipos adenomatosos es de vital importancia. El hallazgo de pólipos hiperplásicos o hamartomatosos, en general, no revierte problemas; son los adenomas los que nos deben preocupar, especialmente se éstos son mayores de un centímetro. Los pólipos deben ser extirpados en su totalidad. Si en la pieza extirpada se demuestra la existencia de carcinoma in situ debe asegurarse la remoción completa con márgenes libres. Se recomienda que los pólipos sésiles malignos sean tratados con cirugía convencional, con criterio oncológico

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.

Colon cancer: morphology detected with barium enema examination versus histopathologic stage.

PURPOSE: To determine the relationship between the morphology of colon carcinomas detected with barium enema examination and the cancer stage. MATERIALS AND METHODS: Clinical, radiographic, endoscopic, surgical, and histopathologic findings were retrospectively reviewed in 152 patients with colon cancer detected with barium enema examination during a 2-year period. RESULTS: Eighty-six patients (57%) had lesions in the rectum and sigmoid and descending colon, and 66 (43%) patients had lesions more proximally in the colon. Lesions on the right side of the colon were less likely to cause symptoms than those on the left side. Eighty-one patients (53%) had annular or semiannular lesions, 57 (38%) had polypoid lesions, and 14 (9%) had plaquelike or carpet lesions. Six patients (4%) had Dukes stage A lesions; 84 (55%), Dukes stage B lesions; 42 (28%), Dukes stage C lesions; and 20 (13%), Dukes stage D lesions. CONCLUSION: Annular or semiannular carcinomas had higher rates of serosal invasion and lymph node metastasis than polypoid carcinomas, but the rates of liver metastases were comparable.

Malignant risk in juvenile polyposis coli: increasing documentation in the pediatric age group.

The presence of juvenile polyps with resulting bleeding and abdominal pain has traditionally been considered a benign, self-limiting process which would resolve with age. The dictum that these polyps were usually solitary, were found predominantly in the rectosigmoid area, and were without malignant potential has been reconsidered in recent years with the increased use of colonoscopy. Several case reports in both adults and children have documented the presence of adenomatous changes in this syndrome. We report 3 cases of children, ages 3, 11, and 11 who were found to have adenomatous polyps in the midst of fields of juvenile polyps on evaluation for rectal bleeding. All three were treated definitively with endorectal pull-through. Two of these patients had atypia on histological evaluation, one of which was severe. We recommend a more aggressive approach to patients found to have multiple juvenile polyps on barium enema, including colonoscopic biopsies at several sites to determine the presence of adenomatous changes, with colectomy and endorectal pull-through should these be found.