Iliofemoral Venous Thrombosis Mainly Related to Iliofemoral Venous Obstruction by External Tumor Compression in Cancer Patients

BACKGROUND: To study iliofemoral venous thrombosis related to iliofemoral venous obstruction in cancer patients. METHODS: In this case series study, 829 cancer patients were surveyed for iliofemoral obstruction/thrombosis within 10 years. The criteria for inclusion were: (1) presence of unilateral lower-extremity swelling; (2) computed tomography (CT) scans showing a tumor with external compression of the iliac or femoral vein, and (3) duplex ultrasound scans showing venous thrombosis or venous flow insufficiency over a femoral vein or saphenous vein. RESULTS: Sixty-three patients (8%) developed an iliofemoral venous obstruction. The presence of iliofemoral venous thrombosis was detected in 21 of these patients (33%). The rate of iliofemoral venous thrombosis was significantly higher in patients with an invasion of the inguinal region, D-dimer levels >3,000 ng/ml, gastrointestinal cancer, or invasion of the inguinal lymph nodes. However, none of our patients with iliofemoral venous thrombosis had a detection of iliofemoral venous obstruction. Improved lower-extremity swelling was reported in 84% of the patients following combination therapy involving low-molecular-weight heparin (LMWH) and systemic therapy. CONCLUSION: Patients with an iliofemoral venous thrombosis mainly had iliofemoral venous obstruction by external tumor compression. Combination therapy with LMWH and systemic therapy were mandatory for these patients.