Pulmonary metastasis of hepatocellular carcinoma associated with transarterial chemoembolization

Recent advances in both diagnosis and treatment of hepatocellular carcinoma have improved the prognosis and changed the clinical significance of the subsequently increasing distant metastases. Pulmonary metastasis of hepatocellular carcinoma associated with transcatheter arterial chemoembolization has rarely been reported.

To evaluate whether transcatheter arterial chemoembolization increases the risk of pulmonary metastasis of hepatocellular carcinoma, 230 patients were studied. Among them, 156 received transcatheter arterial chemoembolization with an interval of 12-16 weeks, the remaining 74 cases refused transcatheter arterial chemoembolization and received only conservative treatment. All patients were followed up with chest x-ray films taken before transcatheter arterial chemoembolization, during admission or in the out-patient department. The mean follow-up interval was 3.37 +/- 1.51 months.

Pulmonary metastasis was found in 25.6% (40/156) and 8.1% (6/74) of the patients with and without transcatheter arterial chemoembolization (p = 0.002). The median interval between initial diagnosis and pulmonary metastasis was 3.39 +/- 0.08 and 11.72 +/- 2.91 months among patients with and without transcatheter arterial chemoembolization (p = 0.001). The mean age, sex, existence of cirrhosis, severity of cirrhosis, presence of collateral arterial circulation, amount of lipiodol and agent of anti-cancer drugs were not associated with the development of lung metastasis. However, factors predisposing to lung metastasis included: solitary tumor with tumor size > 10 cm, multiple tumors with main tumor > 5 cm or diffuse hepatocellular carcinoma, intrahepatic portal vein thrombosis, arterioportal or arteriovenous shunt, and the presence of incomplete tumor necrosis after transcatheter arterial chemoembolization (especially combined with necrotic area > 50% main tumor size).

Pulmonary metastasis associated with transcatheter arterial chemoembolization has a strong adverse impact on patient survival.