Relationship between Streptococcus gallolyticus Infective Endocarditis and Pre-Neoplastic Colorectal Lesions

Colorectal cancer is associated with Infective Endocarditis (IE) due to specific gut pathogens, such as Streptococcus gallolyticus subspecies, that use tumor presence as a point of blood entry. However, the association between Streptococcus gallolyticus related IE and pre-cancerous colorectal lesions like dysplastic adenomas is unclear. Seventy-one patients diagnosed with IE who underwent colonoscopy in the extension study during admission were included in a clinical, microbiological and imaging follow-up, between January 2008 and December 2020. Pre-cancerous lesions were divided as high and low-grade dysplasia based on World Health Organization criteria. Colorectal cancer was defined as the presence of malignant cell beyond the muscularis mucosa. Twenty-two IE patients (31%) presented colorectal lesions: 8 (36%) colorectal cancer and 14 (64%) pre-cancerous lesions [14% high degree (n = 2); 86% low degree (n = 12)]. Both, colorectal cancer (25% Vs 2%; p = 0.007) and pre-neoplastic lesions (50% Vs 2%; p<0.001) were related with higher prevalence of IE caused by Streptococcus gallolyticus. Additionally, the subgroup of low grade pre-cancerous lesions also showed this association (50% Vs 2%; p<0.001). Pre-cancerous colorectal lesions are associated with Streptococcus gallolyticus IE. These results suggest that high and low degree colorectal lesions may also act as a gateway for gut pathogens.