Detection of FIT- , fecal- and mucosa associated microbiome and microRNA in patients with suspected colorectal adenomas or cancer

Colorectal cancer (CRC) is one of the major causes of death in the Netherlands, accounting for almost 5000 deaths in 2014. As most CRCs may develop slowly over years from precursor lesions, screening and early diagnosis are key to disease prevention. Nowadays faecal immunochemical testing (FIT), a marker to detect human haemoglobin, is used as a screening tool for CRC. However, not all lesions bleed, and conversely, occult blood can on occasion be detected in fecal samples of otherwise healthy individuals. While the sensitivity of FIT tests for CRC is around 79%, its specificity for advanced adenomas is only 50%. Thus, additional tools to identify individuals at risk for CRC, and to reduce the burden of unnecessary procedures, are called for. Recently, an association was made between the microbiome and carcinogenesis. This new development could lead to new markers for the screening of colorectal cancer. In addition, microRNA (MiRNA) seems to be a modulator in the tumour process as a result of their role in cell proliferation, differentiation and apoptosis, and have been suggested to be a stable, valuable biomarker for tumorigenesis. Until now, the majority of the studies assessed the microbiome and mircroRNA through faecal samples. However, mucosal tissue and luminal content show considerable differences in microbial composition. Furthermore, very little is known on microbiome and miRNA composition in FIT fluid. The aim of the current study is to investigate whether or not the microbiome and miRNA can be detected in FIT samples, and function as additional biomarkers for CRC and adenomas.

Secondly, we would like to evaluate whether or not the microbiome and miRNA differs in composition and diversity when analyzed from FIT, fecal sample and mucosal samples.

n.a.

The patient has to perform two FITs and one stool sample. One extra mucosal biopsy will be taken of found adenomas or CRC only in those patients undergoing a colonoscopy. A questionnaire about dietary and lifestyle habits will be filled out.