The purpose of this study is to determine the clinical utility of stool and blood methylation tests for detection of advanced mucosal neoplasia (AMN) and sessile serrated polyps (SSP).
By not only diagnosing colorectal cancer (CRC) at an early stage, but also removing precursor lesions (adenomas), colonoscopy with polypectomy reduces the risk of developing and dying from CRC. Approximately 90% of polyps are less than 10 mm and are easily removed by competent endoscopists. Laterally spreading lesions (LST) and sessile lesions of the colon, also known as advanced mucosal neoplasia (AMN) are underrecognised types of lesions that are more likely to progress to cancer. They include sessile serrated polyps (SSP), an emerging entity of flat polyps with malignant potential. Detection of hemoglobin (a component of blood) in stool is an established validated screening tool for CRC. Its specific role in the prediction of AMN, and particularly SSPs is yet to be defined. Blood tests measuring the level of tumour derived methylated deoxyribonucleic acid (DNA) in blood circulating have been demonstrated to have clinical utility for detection of CRC and AMN. A blood based CRC screening test has the potential to increase compliance. This study aims to determine the clinical utility of stool and blood methylation tests for detection of AMN and SSPs. Stool and blood will be obtained from consenting patients referred for endoscopic removal of known ANM and SSP (study arm) as well as from consenting patients scheduled for colonoscopy screening (control arm). The level of stool hemoglobin and methylated tumour derived DNA in circulation will be measured in the two study groups. Cutoff values will be generated to assess best predictive capability of high risk lesions based on these tests.
Study Type
OBSERVATIONAL
Enrollment
205
blood or stool samples will be collected
Westmead Endoscopy Unit
Westmead, New South Wales, Australia
Demographics
Data to adequately describe demographic situations of each participant.
Time frame: 1 day
Level of methylated DNA in circulation
The process will use an automated extraction procedure incorporating state-of-the-art magnetic silica-coated beads on a QIASymphony (Qiagen). The extracted DNA is bisulphite-converted and further purified (automated on a QIACube HT liquid handler) prior to analyzing 12uL of bis-DNA in a multi-plexed (BCAT1, IKZF1, ACTB (control assay)) real-time PCR for measuring the methylation levels of target amplicons.
Time frame: 5 years
Level of haemoglobin in stool
Suspended stool collected in the HM-JACKarc sampling device will be processed for Hb measurements using commercially available reagents and the bench-top analyser instrument, HM-JACKarc, according to manufacturer recommendation (Kyowa Medex Co Ltd, Japan). Measured haemoglobin concentrations will be reported as ug Hb/g stool. A 20 ug Hb/g stool a cut-off concentration will be used for qualitative reporting.
Time frame: 5 years
Demographics
Data to adequately decribe the clinical situations of each participant.
Time frame: 1 day
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