Faecal dimeric M2 pyruvate kinase in colorectal cancer and polyps correlates with tumour staging and surgical intervention.
OBJECTIVE
A dimeric form of pyruvate kinase isoenzyme (tumour M2-PK) is predominantly found in highly proliferating cells. Sandwich ELISA with monoclonal antibodies against dimeric (tumour) M2-PK was used to measure faecal tumour M2-PK in; 13 controls, 10 patients with colonic polyps and 32 patients with colorectal cancer.


RESULTS
Levels of faecal tumour M2-PK were higher in patients with colorectal cancer (median 11.72 U/ml; range 0.9-146.95 U/ml, P = 0.0001) and polyps greater than 10 mm (median 2.54 U/ml; range 0.9-29.46 U/ml, P = 0.041) when compared with controls (median 1.75 U/ml; range 0.9-3.41 U/ml). Furthermore, levels were higher in stages Duke's B (P = 0.013) and Duke's C (P = 0.43) than in Duke's A. Six months postsurgery faecal tumour M2-PK levels fell significantly to 3.46 U/ml (range 1.03-9.05 U/ml, P = 0.001). The sensitivity of a positive faecal tumour M2-PK test, defined as a level above 3.33 U/ml, was 91% for colorectal cancer, 60% for >10 mm and 20% for <10 mm polyps, with a specificity of 92%.


CONCLUSIONS
Faecal tumour M2-PK is a highly sensitive marker for colorectal cancer and larger polyps. It also correlates with more advanced stages of colorectal cancer and its reduction is associated with successful surgical intervention.
Koss
K
K
Gastroenterology Department, Macclesfield District General Hospital, Maccelsfield, UK. konradkoss@yahoo.com
Maxton
D
D
Jankowski
J A Z
JA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D016022:Case-Control Studies; D003082:Colectomy / Q000379:methods / Q000401:mortality; D003111:Colonic Polyps / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D005243:Feces / Q000201:enzymology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009780:Occult Blood; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D011770:Pyruvate Kinase / Q000032:analysis*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D016019:Survival Analysis