-
World Journal of Gastrointestinal... Mar 2022Recently, there have been several findings that showed intestinal colonisation of () as a risk factor to the worsening of colorectal cancer (CRC). However, studies have...
BACKGROUND
Recently, there have been several findings that showed intestinal colonisation of () as a risk factor to the worsening of colorectal cancer (CRC). However, studies have shown controversial results in the pathogenicity of .
AIM
To review systematically the evidence available on the association between CRC and and the prevalence of in CRC patients and to investigate cytopathic and immunological effects of in and studies.
METHODS
PRISMA guidelines were utilised in conducting this systematic review. Original articles published before February 2, 2020 were included. PubMed, Science Direct, Scopus and Google scholar databases were searched. Manual searching was carried out to find articles missed during the online search.
RESULTS
Out of 12 studies selected for this systematic review, seven studies confirmed the prevalence of and found it to be between 2%-28% in CRC patients, whereby subtype 1 and subtype 3 were predominantly seen. A total of four studies employing human colorectal carcinoma cell line study models showed significant cytopathic and immunological effects of . In addition, one experimental animal model study showed that there was a significant effect of infection with on exacerbation of colorectal carcinogenesis.
CONCLUSION
is a commonly identified microorganism in CRC patients. These studies have provided supportive data that could exacerbate existing CRC alteration in host immune response and increased oxidative damage. Future studies of CRC and should attempt to determine the various stages of CRC that are most likely to be associated with and its relationship with other intestinal bacteria.
PubMed: 35321272
DOI: 10.4251/wjgo.v14.i3.734 -
Infectious Agents and Cancer Jun 2022Intestinal protozoa Blastocystis hominis and Cryptosporidium spp. are two influential factors in intestinal complications and malignancies. In present study, we... (Review)
Review
OBJECTIVE
Intestinal protozoa Blastocystis hominis and Cryptosporidium spp. are two influential factors in intestinal complications and malignancies. In present study, we estimated the pooled prevalence and odds ratio (OR) of the two parasites in colorectal cancer (CRC) patients and their possible association with the deadly disease.
METHOD
Our systematic search was conducted for published researches between January 1, 2000 and April 30, 2022 by using four international databases include Scopus, PubMed, and Web of Science as well as Google scholar search engine. The random- and fixed-effects models were used to estimate the pooled prevalence, OR, and 95% confidence interval (CI) by comprehensive meta-analysis (V2.2, Bio stat) software. Inclusion and exclusion criteria were applied.
RESULTS
Thirteen papers (seven case-control and six cross-sectional studies) for B. hominis/CRC and six papers (two case-control and four cross-sectional studies) for Cryptosporidium spp./CRC were eligible to include in data synthesis. Pooled prevalence of B. hominis and Cryptosporidium spp. in CRC patients was calculated to be 26.8% (95% CI 19.4-35.7%) and 12.7% (95% CI 6.8-22.5%), respectively. Based on case-control studies, significant difference was found between case and controls in both protozoa (B. hominis OR 2.10; 95% CI 1.39-3.18% vs. Cryptosporidium spp. OR 5.06; 95% CI 1.8-13.6%). Considering the Blastocystis subtypes, ST1 (5/6; 83.33% studies) and ST3 (5/6; 83.33% studies) had the highest number of reports in CRC patients. Regarding the Cryptosporidium species, only C. parvum and C. hominis were reported.
CONCLUSION
Given the significant prevalence of both parasites in CRC patients and their statistically significant association, there is a need to pay more attention to these two intestinal parasites in under treatment patients.
PubMed: 35715853
DOI: 10.1186/s13027-022-00447-x