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.