Validation of Faecal Pyruvate Kinase Isoenzyme Type M2 (faecal M2PK Quick) Test in Detection of Colorectal Adenoma and Adenocarcinoma among High-Risk Malaysian Population.

BACKGROUND:Colorectal neoplasia is a multistep process that can lead to the development of colorectal cancer. Colonoscopy is the gold standard for diagnosis and screening of colorectal cancer, but its uptake is often hindered by unpleasant experiences and logistic obstacles. Therefore, non-invasive biomarker tests such as the M2-pyruvate kinase (M2PK) test have been explored as a potential screening tool.OBJECTIVE:This study aims to evaluate the efficacy of the M2PK Quick Stool Test (ScheBo®) in detecting colorectal adenoma and adenocarcinoma in high-risk Malaysian populations using colonoscopy as the comparison.METHODS:A prospective, cross-sectional, multicenter study was conducted from December 2017 to December 2019 in four hospitals in Malaysia. Participants were eligible if they met any of the following criteria: personal or family history of colorectal polyps or cancer, inherited syndromes, altered bowel habits, rectal bleeding, unintended weight loss, loss of appetite, abdominal pain or cramps, or unexplained iron deficiency, or an Asia-Pacific Colorectal Screening score of 4-7. Participants provided a stool sample that was tested for M2PK using the M2PK Quick Test. Participants then underwent a colonoscopy, and any lesions found were biopsied and sent for histopathological examination.RESULTS:A total of 562 participants were included in the study, of whom 89 had a positive M2PK test. Presence of adenoma and/or dysplastic lesions were confirmed in 14.4% and adenocarcinoma in 3.0% of the participants. The M2PK Quick Stool Test showed a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 58.8%, 85.5%, 11.2% and 98.5%, respectively in detecting colorectal adenocarcinoma. For detection of colorectal adenoma, this test yielded a sensitivity, specificity, PPV and NPV of 27.3%, 86.3%, 27.0% and 86.5%, respectively.CONCLUSIONS:The M2PK Quick Stool Test showed a moderate accuracy in detecting colorectal adenocarcinoma and adenomas in the studied population.