Clinical value of a diagnostic score for colon cancer based on serum CEA, CA19-9, cytokeratin-1 and mucin-1.

ABSTRACT

BACKGROUND: Although established markers such as CEA and CA19-9 are important for diagnosing early stages of colon cancer, they are not ideal. Developing promising markers include cytokeratin 1 (CK1) and mucin-1 (MUC1), but the combined value of each of these markers is unclear. We therefore evaluated the value of a combined laboratory-based score of these four markers in the diagnosis of colon cancer. METHODS: Two hundred patients who had undergone colonoscopic examination (150 colon cancer, 50 benign growths) were recruited. The study was controlled by 35 healthy subjects. CEA, CA19-9, CK1 and MUC1 were measured by ELISA and evaluated for cancer diagnosis using area under the receiver operating characteristic curve (AUC). RESULTS: Serum levels of all four markers were increased in the order colon cancer > benign disease > healthy controls (p < 0.001). In multivariate analysis, CA19.9 (p = 0.025), CK1 (p < 0.001) and MUC1 (p = 0.009) were significant independent predictors of colon cancer. A score that gave the greatest power of discrimination for colon cancer was defined as 1.06 + [0.001 × CA19.9 result] + [0.003 × CEA result] + [0.03 × CK1 result] + [0.05 × MUC1 result]. The colon score provided superior discrimination, AUC, and sensitivity and specificity for colon cancer versus benign growth than each of the individual markers. Similarly, the colon score provided superior AUC, and sensitivity and specificity that each individual marker for tumour stage, lymph node invasion and distant organ metastases than each individual marker. CONCLUSION: A colon score derived from serum CEA, CA19-9, CK1 and MUC1 is a potential valuable non-invasive index that could be used for detection and screening early stage colon cancer patients.