Measurement of fecal pyruvate kinase type M2 (tumor M2-PK) concentrations in patients with gastric cancer, colorectal cancer, colorectal adenomas and controls.

The determination of Tumor M2 Pyruvate Kinase (Tumor M2-PK) in EDTA plasma has been described as a tumor marker in a variety of different tumor types. Since most GI tumors grow intraluminally, it appeared interesting to determine whether Tumor M2-PK is detectable in the feces of tumor patients. Measurements were performed with a commercially available ELISA (ScheBo Biotech AG, Giessen, Germany) modified for fecal analysis. Samples of controls, GI cancer and adenoma patients were tested. Fecal Tumor M2-PK concentrations could be quantified. A significant difference between cancer patients and controls was found. The highest concentrations were observed in colorectal cancer. However, fecal Tumor M2-PK was not detectable in 5 tumor patients. The measurement of fecal Tumor M2-PK concentrations might provide an interesting screening tool for colorectal cancer. Further studies comparing the determination of Tumor M2-PK in stool to occult blood in stool are in progress.