bovis/gallolyticus were found in proliferative lesions, 15% of cancers and 21% of adenomas. A recent study
done by our team supported this concept [39] showing that the level of S. bovis/gallolyticus IgG antibodies in adenoma patients was higher than in colorectal cancer patients or control subjects. However, Burns et al. [75] did not get the same findings; they found that the incidence of S. bovis/gallolyticus carriage in all colons with polyps was intermediary between normal colons and colons with carcinoma; however, the difference did not achieve statistical significance. Since there is evidence that colon cancer progresses from normal tissue to adenoma and then to carcinoma through an accumulation of genetic alterations #GW572016 randurls[1|1|,|CHEM1|]# [80], Selleckchem HKI 272 the remarkable association between S. bovis/gallolyticus and adenomatous polyps seems to be of importance. Although ulceration
of neoplastic lesions might form a pathway for S. bovis/gallolyticus to enter the bloodstream [7], the association of S. bovis/gallolyticus bacteremia with non-ulcerated colonic polyps indicates an etiological/promoter role of S. bovis/gallolyticus in polyps progression [81, 82]. Therefore, the possibility of S. bovis/gallolyticus to act as a promoter for the preneoplastic lesions worths consideration. Ellmerich et al. [37] supported this hypothesis. They treated normal rats with S. bovis wall extracted antigens; rats did not develop hyperplastic colonic crypts; however, 50% of rats, that already received a chemocarcinogen, developed neoplastic lesions upon receiving S. bovis wall extracted antigens. This indicated that S. bovis/gallolyticus might exert their carcinogenic
activity in colonic mucosa when preneoplastic lesions are established. Therefore, the role of S. bovis/gallolyticus in the etiology and/or acceleration of the transformation of aberrant crypts to adenoma and to a cancer is being considered. Accordingly, the knowledge of S. bovis/gallolyticus association with adenoma of colorectal mucosa has important clinical implications. If colorectal lesions could be discovered at an early Meloxicam stage, curative resection might become possible [83]. Thus, bacteremia due to S. bovis/gallolyticus should prompt rigorous investigation to exclude both endocarditis and tumors of the large bowel [82, 84]. Therefore, it was concluded that the discovery of a premalignant proliferative lesion in patients with history of bacteremia/endocarditis justifies the exploration of the colon by barium enema and/or colonoscopy [82, 84]. Etiological versus non-etiological role of S. bovis/gallolyticus in the development of colorectal tumors The underlying mechanisms for the association of S. bovis/gallolyticus bacteremia/endocarditis with colorectal tumors have long been obscure. The possible reason behind that, maybe, S. bovis/gallolyticus is a member of intestinal flora in 2.5 to 15% of individuals; this usually leads scientists to counteract the malicious role of this bacteria [44, 75].