Article

Infectious Agents and Colorectal Cancer: A Review of Helicobacter pylori, Streptococcus bovis, JC Virus, and Human Papillomavirus

Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, 1100 Fairview Avenue North, M4-B402, Seattle, WA 98109, USA.
Cancer Epidemiology Biomarkers & Prevention (Impact Factor: 4.13). 12/2008; 17(11):2970-9. DOI: 10.1158/1055-9965.EPI-08-0571
Source: PubMed

ABSTRACT

Based on the high volume of bacteria and viruses that the intestine is exposed to and the importance of infectious agents in some gastrointestinal and anogenital cancers, it is not surprising the many studies have evaluated the association between colorectal cancer and infectious agents. This review highlights investigations of four agents in relation to colorectal cancer. Helicobacter pylori, Streptococcus bovis, JC virus, and human papillomavirus have all been evaluated as possible etiologic agents for colorectal cancer. For each of these agents, a review of possible mechanisms for carcinogenesis and epidemiologic evidence is discussed, and future directions for research are proposed.

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    • "Several species of bacteria have been linked to chronic infections of colon and have been shown to increase the risk of colon cancer. Streptococcus bovis has been evaluated as one of the possible etiologic agents for colorectal cancer [1]. S. bovis is a Gram-positive bacterium, which is considered as a normal inhabitant of the human gastrointestinal tract but is less frequently present than other Streptococcus species [2]. "
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    ABSTRACT: Streptococcus bovis is a Gram-positive bacterium causing serious human infections, including endocarditis and bacteremia, and is usually associated with underlying disease. The aims of the current study were to compare prevalence of the bacterium associated with malignant and nonmalignant gastrointestinal diseases and to determine the susceptibility of the isolated strains to different antimicrobial agents. The result showed that the prevalence of S. bovis in stool specimens from patients with malignant or with nonmalignant gastrointestinal diseases was statistically significant. This result may support the idea that there is correlation between S. bovis and the malignant gastrointestinal diseases.
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    • "As in the case of prevalence of HPV in CRCs, the papers published on the presence of JCV T-antigen sequence in CRCs display contradictory results with frequencies ranging from 0% in Italian and Spanish study, through 26% in Japanese cases to 77% in American patients [13, 34–36]. Given the all above-cited studies based on relatively similar PCR approaches, the discrepancies of JCV frequencies in CRC may reflect ethnic-dependent epidemiology of JCV or lack of reliable and reproducible test for the detection of JCV DNA [37]. A previous study by Goel et al. [13] reported an association between JCV T-antigen expression and methylation of the promoter region of various cancer-related genes in colorectal cancer. "
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    • "⁄ p < 0.05 vs. sham-operated mice. and pharmacological agents[4]. Intake of pharmacological agents, namely non-steroidal anti-inflammatory drugs (NSAIDs), can be effective; however, long-term intake could cause adverse reactions and even fatal side effects[8]. Considering the reports from epidemiological surveys that indicated an inverse correlation between the intake of fruits/vegetables and tumor development[38,39], we presumed that certain dietary phytochemicals might be suitable candidates that can suppress carcinogenesis[40]. "
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