Current state and future direction of screening tool for colorectal cancer

Indications and Diagnostic Yield of Colonoscopy in Kano, Nigeria

Context:

Colonoscopy is the investigation of choice for colonic lesions and has been widely used to diagnose and treat various colonic diseases. As essential as it is, colonoscopy is not readily available in Nigeria, particularly in Kano, therefore, the study on the indication and diagnostic yield of colonoscopy is necessary in our environment.

Aim:

To determine the appropriateness of indications for the colonoscopy and the colonoscopy diagnostic yield in resource-limited environment.

Method:

The study is a cross-sectional descriptive study of patients referred for colonoscopy in our center during the study period between November 2013 and June 2014. Sixty patients referred to our Endoscopy Unit were consecutively recruited during this period. The data generated were analyzed using a computer-based SPSS version 16.0. The variables were presented as percentages and tables.

Results:

Largely, the indication for the colonoscopy is lower gastrointestinal bleeding accounting for 70.0%, while changing bowel habits, chronic constipation, and diarrhea among other indications accounted for the remaining 30.0%. Similarly, the diagnostic yield defined in the study as the presence of serious colonic lesions was 25%. A serious colon lesion is the presence of malignancy, pre-malignant lesions, or pathology with devastating clinical outcomes.

Conclusion:

Colonoscopy is the gold standard in the evaluation of colonic lesions, and no single or combination of tests is as sensitive in identifying pre-malignant or malignant lower gastrointestinal conditions. The study shows that rectal bleeding is the singular most important indication for colonoscopy with higher diagnostic yield.

Biochemical assessment of the neurotoxicity of gold nanoparticles functionalized with colorectal cancer-targeting peptides in a rat model

The application of gold nanoparticle-peptide conjugates as theranostic agents for colorectal cancer shows much promise. This study aimed at determining the neurotoxic impact of 14 nm gold nanoparticles (AuNPs) functionalized with colorectal cancer-targeting peptides (namely p.C, p.L or p.14) in a rat model. Brain tissue samples, obtained from Wistar rats that received a single injection of citrate-capped AuNPs, polyethylene glycol-coated (PEG) AuNPs, p.C-PEG-AuNPs, p.L-PEG-AuNPs or p.14-PEG-AuNPs, and sacrificed after 2- and 12-weeks, respectively, were analysed. Inflammation marker (tumour necrosis factor-α, interleukin-6, interleukin-1β), oxidative stress (superoxide dismutase, catalase, glutathione peroxidase) and apoptotic biomarker (cytochrome c, caspase-3) levels were measured. Gold nanoparticle-treated groups sacrificed after 2-weeks did not exhibit any significant inflammatory, oxidative stress or apoptotic effects in brain tissue compared to the untreated control group. In brain tissue from rats that were exposed to citrate-capped AuNPs for 12-weeks, tumour necrosis factor-α and interleukin-6 levels were significantly increased compared to the untreated control. Exposure to PEG-AuNP, p.C-PEG-AuNP, p.L-PEG-AuNP and p.14-PEG-AuNP did not elicit significant toxic effects compared to the control after 12-weeks, as evidenced by the absence of inflammatory, oxidative stress and apoptotic effects in brain tissue. We thus report on the safety of PEG-coated AuNP-peptide conjugates for potential application in the diagnosis of colorectal cancer; however, exposure to citrate-capped AuNPs could induce delayed neuro-inflammation, and as such, warrants further investigation.