Progress in the treatment of pulmonary metastases after liver transplantation for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world, and is the third leading cause of cancer-related death. Liver transplantation (LT) has become a curative treatment for patients with HCC. However, recurrence and metastasis after LT are the main factors reducing long-term survival in patients, and the lung is the most common site of metastasis after LT for HCC, although metastasis to liver, para-aortic lymph nodes and renal periphery are observed. Thus, the treatment of pulmonary metastases after LT for HCC has become a hot research topic, the successful treatment of pulmonary metastases can significantly prolong the survival of LT patients. Although single conventional treatment (chemotherapy, surgery and external beam radiation therapy), immunosuppression, image-guided minimally invasive therapy (radiofrequency ablation, microwave ablation, cryoablation, and brachytherapy) and molecular targeted drugs have had a significant effect, patients do not have durable remission and the long-term survival rate is disappointing. Therefore, improving existing treatments and identifying a more effective combination therapy are important research issues in the prevention and treatment of pulmonary metastases after LT for HCC. The paper reviewed single conventional treatments, new treatments, and combination therapy, to provide a basis for the best treatment of these patients.