Portal vein tumor thrombus is a bottleneck in the treatment of hepatocellular carcinoma

The effect of portal vein tumor thrombus (PVTT) on the prognosis of patients with hepatocellular carcinoma has become clearover the past several decades. However, identifying the mechanisms and performing the diagnosis and treatment of PVTT remainchallenging. Therefore, this study aimed to summarize the progress in these areas. A computerized literature search in Medlineand EMBASE was performed with the following combinations of search terms: “hepatocellular carcinoma” AND “portal veintumor thrombus.” Although several signal transduction or molecular pathways related to PVTT have been identified, the exactmechanisms of PVTT are still largely unknown. Many biomarkers have been reported to detect microvascular invasion, but nonehave proved to be clinically useful because of their low accuracy rates. Sorafenib is the only recommended therapeutic strategy inWestern countries. However, more treatment options are recommended in Eastern countries, including surgery, radiotherapy(RT), transhepatic arterial chemoembolization (TACE), transarterial radioembolization (TARE), and sorafenib. Therefore, weestablished a staging system based on the extent of portal vein invasion. Our staging system effectively predicts the long-termsurvival of PVTT patients. Currently, several clinical trials had shown that surgery is effective and safe in some PVTT patients. RT,TARE, and TACE can also be performed safely in patients with good liver function. However, only a few comparative clinical trialshad compared the effectiveness of these treatments. Therefore, more randomized controlled trials examining the extent of PVTTshould be conducted in the future.