beta-carotene and Intestinal-Polyps

One hundred and sixteen patients were included, during 18 months, in a double-blind placebo-controlled intervention study, with calcium, vitamins A, C, E and selenium (in a cocktail) or placebo against growth of colonic polyps. Patients were randomized within three arms, according to diameter of the largest polyp, < 5 mm, 5-9 mm or > 9 mm. Polyps > 9 mm were resected, the others were left to be measured annually before resection after 3 years. The protocol (performed in all of the patients) included registration of demographic data, family and personal history, measurement of polyps, collection of blood specimens, stools and biopsy samples. Registration of nutritional status, diet history and 5-day prospective food consumption, was performed in 108 patients. The patient compliance was registered every third month by the hospital pharmacist, with concomitant delivery of new boxes of capsules. Additionally, stool collections were performed from all of the patients for the measurement of faecal calcium, bile salts and fat. Inclusion rate of 37, 41 and 38 patients in each of the three 6-month periods was uniform. The group with the largest polyps measuring 5-9 mm comprised 44% of the material. The sex ratio corresponded to that in overall referrals for colonoscopy. The age relationship of size and multiplicity of polyps and the distribution of polyps in the large bowel corresponded to previous experience in polyp-bearing individuals of the same age.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Age Factors; Aged; Ascorbic Acid; beta Carotene; Calcium; Carotenoids; Colonic Polyps; Colonoscopy; Combined Modality Therapy; Double-Blind Method; Feces; Feeding Behavior; Female; Humans; Intestinal Polyps; Male; Middle Aged; Patient Compliance; Placebos; Prospective Studies; Rectal Neoplasms; Selenium; Vitamin E

Several retrospective and prospective epidemiological investigations have demonstrated that a diet rich in carotenoids could prevent the development of pre-cancerous and neoplastic lesions of the digestive tract. The aim of this examination was to analyse the correlation between colorectal polyps with different histological classifications and serum carotenoid levels.. A 10 ml blood sample was taken from all of the patients after the colonoscopic diagnosis. The serum levels of vitamin A, lutein, zeaxanthin, alpha- and beta-cryptoxanthin, alpha- and beta-carotene were measured in patients with adenomatous colorectal polyp (n = 59, 35 males, 24 females) by high-pressure liquid chromatography (HPLC) and compared with those in healthy subjects (n = 20, 10 males, 10 females). The patients were separated into four groups depending on their histological findings.. The serum levels of vitamin A and zeaxanthin were significantly lower in all patients with polyps (vitamin A: 0.913 +/- 0.112 micromol/l, zeaxanthin: 0.071 +/- 0.012 micromol/l) than in the control healthy group (vitamin A: 2.036 +/- 0.354 micromol/l, zeaxanthin: 0.138 +/- 0.048 micromol/l). The lowest levels were found in patients with focal adenocarcinoma in the polyp. There were no significant differences in the serum levels of other carotenoids. The serum levels of cholesterol, haemoglobin, total protein and albumin were normal in these patients.. There are close and inverse correlations between the serum level of carotenoids and colorectal polyps with different histological grades. The low mean carotenoid levels in patients with adenocarcinoma in the polyp indicate that deficiency of carotenoids may be an important factor in the development of colorectal cancer.

Topics: Adenocarcinoma; Adenomatous Polyps; beta Carotene; Blood Proteins; Carotenoids; Cholesterol; Chromatography, High Pressure Liquid; Colonic Polyps; Colonoscopy; Cryptoxanthins; Female; Hemoglobins; Humans; Intestinal Polyps; Lutein; Male; Middle Aged; Rectal Neoplasms; Serum Albumin; Vitamin A; Xanthophylls; Zeaxanthins

Colonic crypt cell proliferation is used as an indicator of risk of colorectal carcinoma. Subjects with adenomatous polyps and cancer have an increased cell proliferation and a shift of the proliferative zone towards the apex of the crypt. Epidemiological and in vitro studies have confirmed a link between vitamins A, E, C, beta-carotene, and colorectal cancer. In vitro bromodeoxyuridine immunohistochemical technique was used to assess the effect of daily oral supplementation with vitamin E (160 mg), vitamin C (750 mg), or beta-carotene (9 mg) on the colonic crypt cell proliferation in patients with adenomatous polyps (n = 40) compared with normal subjects with no colonic disease (n = 20). The patients were given supplementation for one month and colonic biopsy specimens were taken before and at the end of the trial. Patients with adenomatous polyps had a significantly higher mean labelling index per cent than controls (p < 0.001). Vitamin C or beta-carotene supplementation, however, significantly reduced the total proliferation (p < 0.005) whereas vitamin E supplementation had no effect on the colonic crypt cell proliferation. beta-carotene reduced cell proliferation at the base of the crypt only. Vitamin C reduced cell proliferation in all the crypt compartments from the apex to the base to those values seen in age and sex matched controls. These findings indicate that prolonged supplementation with vitamin C may reduce the recurrence of adenomatous polyps.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Antioxidants; beta Carotene; Carotenoids; Cell Division; Female; Humans; Immunohistochemistry; Intestinal Mucosa; Intestinal Polyps; Male; Middle Aged; Vitamins

Breath methane and hydrogen, plasma acetate, serum selenium, vitamin A and beta-carotene were measured in 47 patients from whom colonic polyps had been removed by endoscopic polypectomy between 3 months and 2 years previously. Patients were compared with 39 control subjects in whom no abnormality was detected during colonoscopy. The proportion of methane exhalers was significantly (p less than 0.0005) higher in patients after polypectomy (66.0%) than in controls (28.2%). Mean plasma acetate was lower (p less than 0.025) in post-polypectomy patients (70.5 microM) than in control subjects (97.1 microM) while breath hydrogen was similar in both groups. The serum concentrations of the antioxidants selenium and beta-carotene showed no differences between the groups whereas vitamin A was higher (p less than 0.01) in serum samples of patients after polypectomy than of controls. These findings indicate that the colonic environment in post-polypectomy patients exhibits certain characteristics which may be related to the formation of benign tumors and possibly colon cancer.

Topics: Acetates; Adult; Aged; Antioxidants; beta Carotene; Breath Tests; Carotenoids; Colonic Neoplasms; Female; Humans; Hydrogen; Intestinal Polyps; Male; Methane; Middle Aged; Selenium; Vitamin A