Angiogenesis inhibition and tumor regression caused by heparin or a heparin fragment in the presence of cortisone.

Heparin or a heparin fragment administered with cortisone inhibited angiogenesis, caused regression of large tumor masses, and prevented metastases. Oral administration of heparin resulted in the release of non-anticoagulant heparin fragments in the serum which, in the presence of cortisone, had similar anti-angiogenic and antitumor effects. Of all the heparin fragments tested, the most potent inhibition of angiogenesis in the presence of cortisone was provided by a hexasaccharide with a molecular weight of about 1600.