Tumor progression after preoperative portal vein embolization.

OBJECTIVE To evaluate tumor growth in a series of patients undergoing liver resection after portal vein embolization (PVE). BACKGROUND The regenerative response after PVE leading to compensatory hypertrophy of the nonembolized liver segments potentially enhances tumor growth. METHODS Portal vein embolization was performed in 28 patients diagnosed with colorectal metastases between 2004 and 2011. Tumor volume was measured by computed tomography (CT) volumetry before and after PVE. Tumor growth rate (TGR) was measured by CT volumetry and compared with that of a non-PVE control group with colorectal metastases of whom 30 had 2 CT scans preoperatively. Also, newly diagnosed tumors in the future remnant liver (FRL) after PVE and after resection were analyzed. RESULTS The median TGR of PVE patients was 0.53 mL/d (interquartile range [IQR], 0.02-1.88) versus 0.09 mL/d (IQR, -0.04 to 0.40; P = 0.03) in non-PVE patients. The TGR was 0.15 (IQR, -0.52 to 0.66) mL/d before PVE and 0.85 (IQR, -0.10 to 1.62) mL/d after PVE in the same patients (P = 0.03). Seven patients (25%) showed new tumor lesions in the FRL after PVE, of whom 3 patients (11%) were not resectable. Patients (8 of 19; 42%) after PVE also showed a higher rate of recurrent metastases in the remnant liver at follow-up than non-PVE patients (1 of 28; 4%). Survival was significantly better for non-PVE patients, with a 3-year survival rate of 77% versus 26% in patients undergoing PVE. CONCLUSIONS Portal vein embolization is associated with increased TGR and new tumor in the FRL and recurrent tumor after resection. Short intervals and interval chemotherapy between PVE and resection are, therefore, advised.