The usefulness of a novel screening kit for colorectal cancer using the immunochromatographic fecal tumor M2 pyruvate kinase test

Background/Aims: M2 pyruvate kinase (M2-PK) is an enzyme that is produced in undifferentiated and proliferating tissues. This study aims to evaluate the usefulness of the immunochromatographic M2 pyruvate kinase (iM2-PK) for the screening of colorectal cancer (CRC) and premalignant lesions. Methods: Healthy volunteers and patients with colorectal neoplasia were enrolled in six academic hospitals in the capital province of Korea. The iM2-PK value was compared with the immunochromatographic fecal occult blood test (iFOBT) and fecal tumor M2-PK enzyme-linked immunosorbent assay (ELISA). Results: A total of 323 subjects were enrolled. The sensitivity of iM2-PK for CRC was 92.8%, which was superior to iFOBT (47.5%, p<0.0001). For adenomatous lesions, the sensitivity of iM2-PK was 69.4%, which was also superior to iFOBT (12.1%, p<0.001). Compared with M2-PK ELISA, iM2-PK exhibited significantly enhanced sensitivity for CRC (97.5% vs 80.0%, p=0.0289). The sensitivity of iM2-PK was higher in advanced stages of CRC compared with cancers confined to the mucosa and submucosa (p<0.05). However, lymph node metastasis had no influence on the sensitivity of iM2-PK. Conclusions: The iM2-PK exhibited increased sensitivity for identifying CRC and adenomatous lesions compared with iFOBT. Given its rapid results and convenience, CRC screening using iM2-PK is promising.