The hypothesis of the present study is that metabolic phenotyping of blood plasma allows to (i) discriminate between colorectal cancer patients and control subjects and (ii) identify new biomarkers for colorectal cancer. In order to test this hypothesis, the investigators will apply proton nuclear magnetic resonance (1H-NMR) spectroscopy to perform metabolic phenotyping of blood plasma in 50 colorectal cancer patients and 50 control subjects. Multivariate statistics will be performed to assess the discriminative power of the applied methodology in distinguishing between both groups and to identify metabolites with potential as biomarkers for colorectal cancer.

Colorectal cancer is one of the most common and deadliest cancers worldwide. Since tumor stage at time of diagnosis is a critical determinant of patient outcome, early detection of colorectal cancer by screening modalities holds the key to improving patient survival. However, current tests, i.e. fecal occult blood testing and colonoscopy, are inadequate for first line screening of colorectal cancer due to limited accuracy and low participation rates, respectively. Therefore, there is an urgent need for new and accurate tests that can be used for en masse screening of colorectal cancer. A blood-based test represents a promising alternative as it takes little time, poses minimal risk to the patient, and is therefore very likely to lead to high participation rates. The development of an effective blood-based screening tool is based on the identification of biomarkers in the blood that are sensitive and specific for colorectal cancer. Studying the metabolic phenotype of colorectal cancer may help to identify such biomarkers since the metabolism of cancer cells is known to differ significantly from that of normal cells. More specifically, the entire metabolism of cancer cells is reprogrammed to increase anabolic reactions that favor cell growth and cell survival.

The hypothesis of the present study is that metabolic phenotyping of blood plasma allows to (i) discriminate between colorectal cancer patients and control subjects and (ii) identify new biomarkers for colorectal cancer. In order to test this hypothesis, The investigators will apply proton nuclear magnetic resonance (1H-NMR) spectroscopy to perform metabolic phenotyping of blood plasma in 50 colorectal cancer patients and 50 control subjects. Multivariate statistics will be performed to assess the discriminative power of the applied methodology in distinguishing between both groups and to identify metabolites with potential as biomarkers for colorectal cancer.

Inclusion Criteria:

• The subject has undergone a colonoscopy or is scheduled to undergo a colonoscopy in the future
• The subject is aged between 40 and 90 years
• The subject understands the study-specific procedures and provides written informed consent before any study-specific procedures are performed

Exclusion Criteria:

• No fasting starting from 10 p.m. the day prior to blood sampling
• Medication intake on the morning of blood sampling
• Diabetes
• History of cancer during the past 5 years
• Treatment for cancer during the past 5 years
• Inflammatory bowel disease

Colorectal cancer patients and control subjects who undergo a coloscopy without diabetes and/or a history of cancer during the past 5 years, of an age between 40 and 90 years and willing to provide written informed consent.