Paired tumor marker of soluble E-selectin and its ligand sialyl Lewis A in colorectal cancer

Background.

Better diagnosis of metastatic disease has been pursued by oncologists; however, many of the tumor markers have been still controversial. Our purpose was to estimate the usefulness of soluble E-selectin and its ligand sialyl Lewis A for more accurate diagnosis as a combined tumor marker for metastases in colorectal cancer. Methods. E-selectin and sialyl Lewis A, collected from preoperative blood, were measured of its levels in 54 patients with colorectal cancer classified according to Dukes' stage. E-selectin was assayed by enzyme-linked immunosorbent assay, whereas sialyl Lewis A was quantified by enzyme immunoassay using immunoclone kit. Results. The elevation in the level of E-selectin was significantly higher in Dukes' D group than that of healthy volunteers (P < 0.001, Fisher's procedure of least significance test), Dukes' A (P = 0.01), B (P = 0.025) and C (P < 0.01). Significantly higher level of sialyl Lewis A was shown in the group of metastases than that of non-metastases (P < 0.0068, Student's t-test). Paired elevation of E-selectin and sialyl Lewis A was significantly higher in the hematogenous metastases than non-metastases (P < 0.001, Fisher exact test). Conclusions. These results suggest that E-selectin could play some role in the progress of hematogenous metastases. The elevation of E-selectin alone or both E-selectin and sialyl Lewis A may be one of the useful indexes for more precise diagnosis of hematogenous metastases of human colorectal cancer.