Prospective cohort comparison of flavonoid treatment in patients with resected colorectal cancer to prevent recurrence

AIM: To investigate biological prevention with flavonoids the recurrence risk of neoplasia was studied in patients with resected colorectal cancer and after adenoma polypectomy. METHODS: Eighty-seven patients, 36 patients with resected colon cancer and 51 patients after polypectomy, were divided into 2 groups: one group was treated with a flavonoid mixture (daily standard dose 20 mg apigenin and 20 mg epigallocathechin-gallat, n = 31) and compared with a matched control group (n = 56). Both groups were observed for 3-4 years by surveillance colonoscopy and by questionnaire. RESULTS: Of 87 patients enrolled in this study, 36 had resected colon cancer and 29 of these patients had surveillance colonoscopy. Among the flavonoid-treated patients with resected colon cancer (n = 14), there was no cancer recurrence and one adenoma developed. In contrast the cancer recurrence rate of the 15 matched untreated controls was 20% (3 of 15) and adenomas evolved in 4 of those patients (27%). The combined recurrence rate for neoplasia was 7% (1 of 14) in the treated patients and 47% (7 of 15) in the controls (P = 0.027). CONCLUSION: Sustained long-term treatment with a flavonoid mixture could reduce the recurrence rate of colon neoplasia in patients with resected colon cancer.

Disparities of conjugating protective enzyme activities in the colon of patients with adenomas and carcinomas

AIM:To investigate the metabolic enzymatic capacity of the colon mucosa to detoxify noxious carcinogenic compounds.METHODS:We investigated the activity of 2 conjugating enzymes-the microsomal uridine glucuronosyltransferase(UGT)and the cytosomal glutathione S-transferase(GST)in the uninvolved mucosa of the colon transversum and sigmoideum in patients with adenomatous polyps and colorectal cancer.Biopsies were taken from the mucosa during colonoscopies which were done for clinical(diagnostic)reasons.After storage,the biopsy material was homogenized and after differential centrifugation the enzyme assays were performed with 4-nitrophenol(UGT)and 1-chloro 2,4-dinitrobenzene(GST)as substrates.RESULTS:About 48 patients were included of which28 had adenomas and 20 had colorectal carcinomas confirmed by histopathology.Enzyme activities were expressed as nmol/mg per minute protein for the GST and as pmol/mg per minute protein for the UGT.Analysis of variance(F-test)indicated that both enzymes were more widely distributed in adenoma than in cancer patients.The means±SD were smaller for cancer patients:GST for adenomas 268±152 vs 241±69 for carcinomas and UGT for adenomas 197±200 vs 150±86 for carcinomas.CONCLUSION:Compared to patients with adenomatous colon polyps those with colorectal carcinoma exhibited a lower capacity of detoxifying enzyme metabolism and their activities clustered over a smaller range.