Prospective case-cohort study of intestinal colonization with enterococci that produce extracellular superoxide and the risk for colorectal adenomas or cancer

Citation
Md. Winters et al., Prospective case-cohort study of intestinal colonization with enterococci that produce extracellular superoxide and the risk for colorectal adenomas or cancer, AM J GASTRO, 93(12), 1998, pp. 2491-2500
Citations number
90
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Gastroenerology and Hepatology
Journal title
AMERICAN JOURNAL OF GASTROENTEROLOGY
ISSN journal
0002-9270 → ACNP
Volume
93
Issue
12
Year of publication
1998
Pages
2491 - 2500
Database
ISI
SICI code
0002-9270(199812)93:12<2491:PCSOIC>2.0.ZU;2-J
Abstract
Objective: The aim of this study was to determine whether intestinal coloni zation with enterococci that produce extracellular superoxide (O-2((.) over bar)), a free radical implicated in the development of colorectal cancer, is associated with these lesions or their precursors. Methods: A prospectiv e case-cohort study was performed by isolating enterococci from stools of c onsecutive patients undergoing colonoscopy who had no prior history of colo noscopy or colorectal cancer. A food frequency questionnaire was also admin istered to control for dietary factors known to affect the risk for these l esions. Results: Among 159 evaluable participants were 77 with no precancer ous or cancerous pathology, 61 with adenomas <2 cm, 10 with adenomas greate r than or equal to 2 cm, and 11 with cancer. Regression analyses found no a ssociations for those subjects with adenomas of any size or with cancer and colonization with Oi-producing enterococci, any nutrient, or age. For thos e patients with large adenomas greater than or equal to 2 cm or cancer, how ever, significant associations were noted for age (OR 1.94 per decade, 95% CI 1.2-3.5), p-carotene (OR 0.44 per 500 mu g/1000 kcal/day, 95% CI 0.2-0.8 ), vitamin A (OR 3.20 per 500 mu g/1000 kcal/day, 95% CI 1.2-8.9), and vita min E (OR 0.09 per 10 mg/1000 kcal/day, 95% CI 0.006-0.9), but not coloniza tion with Oi-producing enterococci. Second stools collected 1 Sr later, how ever, often contained dissimilar enterococcal flora, undermining an importa nt study assumption. Conclusions: Significant associations were found for t hose with large adenomas or cancer (but not small adenomas), with age, and with foods enriched for vitamin A, vitamin E, and p-carotene. An associatio n between colonization with Oi-producing enterococci and colorectal adenoma s or cancer, however, could not be ascertained, possibly because intestinal enterococcal flora changes over time, leaving a potentially cohesive hypot hesis of colon cancer and risk factors as Set unanswered. (C) 1998 by Am. C oll. of Gastroenterology.