High dose calcitriol may reduce thrombosis in cancer patients.

Author(s): Beer TM, Venner PM, Ryan CW, Petrylak DP, Chatta G, Dean Ruether J, Chi KN, Curd JG, DeLoughery TG

Affiliation(s): Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR 97239, USA. beert@ohsu.edu

Publication date & source: 2006-11, Br J Haematol., 135(3):392-4. Epub 2006 Sep 19.

Publication type:

The incidence of venous and arterial thrombosis in a placebo-controlled randomised trial of DN-101 (high dose calcitriol) with docetaxel versus docetaxel was compared. Of the 13 thrombotic events observed in the 250 patients enroled in this study, two occurred in DN-101 and 11 in placebo-treated patients (P = 0.01). This difference remained significant after adjustment for baseline history of thrombosis, atrial fibrillation and use of anti-thrombotic agents. In vitro and vitamin D receptor (VDR) knockout mouse studies predict that nanomolar concentrations of calcitriol may act as an antithrombotic agent. We report the first clinical observation that supports this hypothesis in humans.