Diagnostic Performance of Fecal M2-Pyruvate Kinase for Macroscopic Colorectal Lesions in Suspected Colorectal Cancer

This study aimed to evaluate the diagnostic efficacy of fecal M2-pyruvate kinase (M2PK) in detecting macroscopic colorectal lesions in patients with suspected colorectal cancer (CRC). The study design was comparative, observational, and cross-sectional. Patients aged ≥18 years with symptoms of suspected CRC undergoing colonoscopy at Hasan Sadikin Hospital, Bandung, Indonesia were included in this study, and their fecal specimens were collected prior to procedure. We measured M2PK level by using enzyme-linked immunosorbent assay method. Statistical analysis was then performed, and the macroscopic appearance of the colorectal mucosa at colonoscopy, rather than histopathologically confirmed cancer, was used as the reference standard. p<0.05 was considered significant. Our study showed a significant difference in fecal M2PK levels between patients with positive and negative macroscopic lesions observed by colonoscopy (p<0.001). A cut-off of 4.73 IU/mL yielded a sensitivity and specificity of 92% and 71.4% for detecting macroscopic colorectal lesions, respectively, with an area under the curve of 0.944 (95% CI 0.876–1.000). We suggest that fecal M2PK may serve as a non-invasive triage test to prioritise symptomatic patients for colonoscopy. Because the reference standard was macroscopic and not histopathological, its performance for CRC specifically remains to be confirmed.