Preoperative serum CD26 levels: diagnostic efficiency and predictive valuefor colorectal cancer

CD26 is an ectoenzyme with dipeptidyl peptidase IV activity expressed on a variety of cell types. Although the function of the high concentration of s erum-soluble CD26 (sCD26) is unknown, it may be related to the cleavage of biologically active polypeptides. As CD26 or enzymatic activity levels were previously associated with cancer, we examined the potential diagnostic an d prognostic value of preoperative sCD26 measurements by ELISA in colorecta l carcinoma patients. We found a highly significant difference between sCD2 6 levels in healthy donors (mean 559.7 +/- 125.5 mug l(-1)) and cancer pati ents (mean 261.7 +/- 138.1 mug l(-1)) (P < 0.001). A cut-off at 410 <mu>g l (-1) gave 90% sensitivity with 90% specificity which means that the diagnos tic efficiency of sCD26 is higher than that shown by other markers, particu larly in patients at early stages. Moreover, sCD26 as a variable is not rel ated with Dukes' stage classification, age, gender, tumour location or degr ee of differentiation. With a follow-up of 2 years until recurrence, prelim inary data show that sCD26 can be managed as a prognostic variable of early carcinoma patients. In addition, the origin of sCD26 is discussed. (C) 200 0 Cancer Research Campaign.