Serum levels of midkine, a heparin-binding growth factor, increase in both malignant and benign gynecological tumors

Abstract

Midkine (MK) is a heparin-binding growth factor, the expression of which is strong in the midgestation period, is highly restricted in the adult, and is increased in many human carcinomas. In the present investigation, we determined serum levels of MK by an enzyme immunoassay, and found that in many patients with gynecological tumors, the values increased above the cut off value of 500 pg/ml. All control subjects (n=49) including pregnant women exhibited values not more than 500 pg/ml. The percentage of positive cases was as follows; ovarian carcinoma (n=15), 87%; uterine cervical carcinoma (n=18), 67%; uterine endometrial carcinoma (n=10), 50%; ovarian cyst (n=25), 72%; leiomyoma (n=29), 72%. CA-125 and MK levels were not correlated in ovarian carcinoma and ovarian cyst; a combination of the two assays may be helpful in increasing specificity or sensitivity. Furthermore, increased MK levels were found even in patients with early stages of uterine cervical and endometrial carcinomas. Serum MK levels might become helpful in the initial screening of gynecological tumors.