HPSE and retroperitoneal sarcoma: It should be noted that the heparanase enzyme was previously linked to the development and progression of essentially all tumor types found in the abdominal/pelvic cavity whose radiation treatment may lead to RN (i.e., gastric [9]; colon [4]; ovarian [5] and cervical [6] carcinoma, pancreatic cancer [7,33], retroperitoneal sarcoma [10] and hepatobiliary tumors [34]).