M2-PK, stool

Stool

Tumour M2 pyruvate kinase (M2-PK) is an inactive dimeric form of the M2 isoenzyme of pyruvate kinase (glycolysis enzyme), which occurs increasingly in the course of malignant cell transformation. It is a key enzyme for the regulation of tumour metabolism. Elevated levels in stool specimens can provide early indications of a tumour in the digestive tract. Polyps are also detected. The detection of tumour M2-PK cannot replace colonoscopy as the gold standard in early detection of malignant changes in the intestinal mucosa; however, it has a higher sensitivity and specificity than the test for occult blood in stool. Occult blood does not lead to a positive M2-PK result. Increased: Adenomas, intestinal polyps, chronic inflammatory bowel disease, acute inflammatory bowel disease. Note: a positive result must be further clarified by colonoscopy.