Serum M2-pyruvate kinase: A promising non-invasive biomarker for colorectal cancer mass screening.
OBJECTIVE
To explore the value of serum M2-pyruvate kinase (M2-PK) in colorectal cancer (CRC) mass screening.


METHODS
We conducted a molecular epidemiology study in Hangzhou, China, from year 2006 to year 2008. Serum samples were collected from 93 CRC, 41 advanced adenomas, 137 adenomas, 47 non-adenomatous polyps, and 158 normal participants in a community setting. Serum M2-PK and carcinoembryonic antigen (CEA) were measured using Enzyme-linked immunosorbent assay. SPSS 16.0 software was used to perform data analysis. Area under the receiver operating characteristic curve (AUC), sensitivity, and specificities were estimated for serum M2-PK in diagnosis of colorectal lesions and compared with CEA.


RESULTS
Average serum M2-PK value among 158 normal people was 2.96 U/mL and not affected by gender (P = 0.47) or age (P = 0.59). Average serum M2-PK (U/mL) was 14.75 among stage III and 13.10 among stage I and II CRC patients, about 4 times higher than that among normal people. Average serum M2-PK was 8.58, 6.70, 5.13 and 2.51 U/mL among advanced adenoma, adenomas, non-adenomatous polyps, and inflammatory bowel disease patients, respectively. AUC for serum M2-PK was greater than that for CEA among all colorectal lesions. AUC for serum M2-PK was 0.89 (0.84, 0.94) (95% confidence interval), higher than that for CEA [0.70 (0.62-0.79)] in CRC stage I and II, 0.89 (0.84-0.94) vs 0.73 (0.63-0.83) in CRC stage III, 0.81 (0.74-0.86) vs 0.63 (0.53 - 0.73) in advanced adenomas, 0.69 (0.64-0.76) vs 0.54 (0.47-0.60) in adenomas, and 0.69 (0.62-0.78) vs 0.58 (0.48-0.68) in non-adenomatous polyps. The diagnostic sensitivity for all colorectal lesions increased with decrease in the cut-off value of serum M2-PK. The diagnostic sensitivity (%) of serum M2-PK was 100.00 for CRC, 95.12 advanced adenoma, 82.48 adenoma, and 82.98 non-adenomatous polyp. There were no CRC cases missed and 40.51% of unnecessary colonoscopies were avoided when the cut-off value was 2.00 U/mL.


CONCLUSIONS
Serum M2-PK can be used as a primary screening test in CRC mass screening. It may be a promising non-invasive biomarker for CRC early detection.
Wen Meng, Ze-Feng Xu, Shan-Rong Cai, Qi Dong, Qiang-Rong Pan, Shu Zheng, Su-Zhan Zhang, Zhejiang University Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences), Hangzhou 310009, Zhejiang Province, China.
Wen
W
Meng
Hong-Hong
HH
Zhu
Ze-Feng
ZF
Xu
Shan-Rong
SR
Cai
Qi
Q
Dong
Qiang-Rong
QR
Pan
Shu
S
Zheng
Su-Zhan
SZ
Zhang