OBJECTIVETo investigate the value of measuring the concentration of soluble CD44 splice variant 6 (sCD44v6) in peripheral blood in patients with invasive and non-invasive pituitary adenomas.

METHODSThe concentrations of sCD44v6 in peripheral blood were measured with ELISA in 68 patients with invasive pituitary adenomas and 100 patients with non-invasive pituitary adenomas.

RESULTSThe serum concentration of sCD44v6 in patients with invasive pituitary adenomas was lower than that in patients with non-invasive pituitary adenomas, while the latter was lower than that in healthy controls. The serum concentrations of sCD44v6 were (44.63 +/- 7.21), (34.53 +/- 6.41), and (26.34 +/- 4.95) ng/ml in patients with invasive microadenoma, macroadenoma, and giant adenoma, and (60.78 +/- 9.61), (57.78 +/- 10.00), and (37.22 +/- 5.17) ng/ml in patients with non-invasive microadenoma, macroadenoma, and giant adenoma, lower than that in the healthy control group (68.73 +/- 6.00) ng/ml. Significant differences were observed among groups (P < 0.005). The concentration of sCD44v6 in peripheral blood decreased as the tumor size increased (P < 0.01), which was particularly significant in invasive pituitary adenomas. The positive rate in the patients with invasive pituitary adenomas reached 89.71%.

CONCLUSIONSerum concentration of sCD44v6 in the peripheral blood is inversely correlated with tumor size and its invasive growth, which may provide certain value in the early diagnosis, treatment and prognosis of invasive pituitary macroadenoma and giant adenoma.