ADAMTS-13 activity in patients with brain and prostate tumors is mildly reduced, but not correlated to stage of malignancy and metastasis.

Impaired Von Willebrand factor cleaving activity of ADAMTS-13 was demonstrated in patients with metastasizing and malignant tumors. To investigate the relevance of ADAMTS-13 for tumor progression, we determined ADAMTS-13 activity and VWF:Ag in 80 patients with various malignancies: 30 patients with benign brain tumors, 30 patients with malignant brain tumors, 10 patients with local prostate tumors and 10 patients with metastatic prostate tumors. We found mild ADAMTS-13 deficiency in 17/80 tumor patients, but there was no significant difference in ADAMTS-13 activity between the age- and sex-matched patients with benign and malignant brain tumors nor between the age matched patients with local and metastatic prostate tumors. Patients with malignant brain tumors could only be distinguished from patients with benign tumors by elevated levels of VWF:Ag (p=0.018). Our data are hence in variance to previous studies, which found a distinct inverse correlation between ADAMTS-13 activity and level of metastasis and/or malignancy in diverse cancer-types.