BACKGROUNDSerum tumor markers have always been of clinical importance in the diagnosis, monitoring disease progression and therapy efficacy for patients with malignant diseases. However, elevated serum tumor markers are found in some benign conditions, especially in chronic kidney disease (CKD). The elevation of them in CKD might cause confusion and misuse of these tumor markers. We conducted this retrospective study to investigate which of the five widely used tumor markers including carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), cytokeratin 19 fragment antigen 21-1 (Cyfra21-1), squamous cell carcinoma antigen (SCC) and neuron specific enolase (NSE) are affected markedly by CKD, in order to use them more effectively.

METHODSSerum tumor marker concentrations, biochemical, hematological parameters, and urinalysis were measured in CKD patients and healthy controls. The positive rate and median tumor markers' level in CKD patients and controls, and those in CKD patients stratified by CKD grade were compared using nonparametric rank tests. Correlation analysis of serum tumor markers and other parameters in CKD patients were performed using the Spearman correlation coefficient. Multivariate Logistic regression analysis was used to estimate the important variables that caused elevated serum concentrations of these markers in CKD patients.

RESULTSThe overall positive rates and serum concentrations of Cyfra21-1, SCC, CEA in CKD group were significantly higher than those in control group. Positive rate and serum concentrations of those tumor markers increased as kidney function decreased. Both univariate analysis and multivariate regression analysis showed that the elevations of those tumor markers were not only associated with kidney function, but also with nutritional status.

CONCLUSIONSSerum concentrations of Cyfra21-1, SCC, CEA are significantly influenced by kidney function, as well as nutritional status. Therefore, in clinical work, the indices of kidney function and nutritional status could be simultaneously measured to improve interpretation of the results of those tumor marker concentrations.