The application of C12 biochip in the diagnosis and monitoring of colorectal cancer: systematic evaluation and suggestion for improvement.

BACKGROUND The 12 tumor markers' (TMs) biochip diagnostic (C12) system has been proven useful in some previous studies but its value for colorectal cancer (CRC) only was not systematically investigated. AIMS To evaluate the value of C12 system for CRC. SETTINGS AND DESIGN The associations between TMs and clinicopathological characteristics were evaluated. The most relevant TMs, the most useful combinations, and the correlations between TM levels were assessed. MATERIALS AND METHODS The TMs detected by the C12 system in the sera of 170 pathologically confirmed CRC patients were analyzed. One or more TMs higher than or equal to reference value were defined as positive. STATISTICAL ANALYSIS Chi-square test, Spearman rank correlation test and Receiver-operating characteristic (ROC) curves were used for the analysis. RESULTS The overall positive rate was 41.76%, and was low in stage 0-I (12.90%). Carcinoembryonic cantigen (CEA) had the highest positive rate of 36.47%. The positive rates were significantly correlated to clinical stages and lymph node status, but not to age, sex, tumor location and pathological types. Any combinations of the five highest positive TMs did not have significantly improvements. The levels of three most related TMs (CEA, CA19-9, CA242) of CRC had positive correlation with each other. CA242 and beta-HCG levels were associated with lymph node metastasis. CONCLUSIONS C12 system has some value in advanced CRC, but not in early CRC.