Early Stage Liver Cancer Treatment
Early stage liver cancer (stages 0, A and B) consists of localized HCCs presenting as single masses in one area of the liver or multiple small tumors (3 tumors or less with diameters of 3cm or less). These tumors do not display any vascularization and make up 30% of HCC cases. Early stage liver cancer is typically treated by surgical resection, liver transplantation or ablation which is a minimally invasive treatment that destroys tumor tissue.
Late Stage Liver Cancer Treatment
Advanced stages of liver cancer (stages C and D) are typically treated with transarterial embolization (TAE), transcatheter arterial chemoembolization, targeted therapy and radiation therapy.
Surgical Liver Resection
Strategies used to treat liver cancer depends on multiple factors including liver function, the extent and location of the tumor, and the patients overall health. While no large studies have been done that compare treatment strategies for early stage liver cancer, the gold standard for treating HCC is surgical liver resection and liver transplantation. Patients with localized HCC that will still have sufficient liver functioning after its removal will usually undergo surgical resection.
For patients with extensive cirrhosis, multiple small (smaller than 3cm) lesions, or patients that would have severely impaired liver function if they underwent resection, liver transplantation may be the best option. Unfortunately, because there are few liver donors, this option is not often used.
Ablation is considered when surgical removal of the tumor is not possible, especially for patients with early stage liver cancer. Ablation can be done in multiple ways including increased heat (radiofrequency ablation or microwaves), extreme cold (cryoablation), treatment with chemicals (percutaneous ethanol injection), and damage of the cell membrane (definitive electroporation).
In cases when curative therapies are less likely to be effective, non-curative treatments that extend survival may be provided. These include transarterial chemoembolization, or the injection of anti-cancer drugs into blood vessels that support the liver tumor and the addition of an embolic agent into the vessels to trap the chemotherapy. Sorafenib, a kinase inhibitor used to treat liver and other cancers, may also improve survival.
The most common non-ablative or surgical therapies for HCC is transarterial embolization. TAE involves inserting a catheter into an artery the supports the tumor and injecting small particles (gelatin sponges or beads) into the catheter. These particles block the blood supply to the tumor. Since tumors are hypervascular and typically receive blood from the hepatic artery, a source different than the rest of the liver, blocking arteries that support the tumor deprives the tumor of oxygen, causing tissue death. Alternatively, small embolic particles coated in chemotherapeutics may be injected though the catheter in a procedure called transcatheter arterial chemoembolization (TACE). This method kills the tumor in two ways: i) by blocking the tumors blood supply ii) introducing cytotoxic elements into the tumor. The targeted nature of the therapy may provide additional benefits such as reducing systemic side effects from chemotherapy and an increased tumor response.
Chemotherapies that specifically kill tumor cells are another potential noncurative treatment for advanced stage HCC. Sorafenib is an oral chemotherapy that inhibits multiple proteins called kinases, which support the tumor. Studies have shown that patients taking sorafenib increased the survival time of patients. However, soragenib is associated with side effects including skin reactions on the hands and feet and diarrhea.
Radiation therapy is rarely used since the liver has a low tolerance for radiation. However, developments in the therapy that use breathing-motion management and image-guidance is making it a more viable option.