It is classified into intrahepatic and extrahepatic lesions. Intrahepatic lesions are locally invasive and have a poor prognosis, with a survival time of 3-6 months from diagnosis. Extrahepatic lesions are locally invasive and metastasise late. However, as they invade the liver, portal vein and hepatic arteries at an early stage these tumours are not usually curable. They can arise from any primary tumour, but are particularly common in cancers of the gastro-intestinal tract, of the breast and of melanocytes.
Most liver metastases are asymptomatic and therefore can be extensive prior to diagnosis.
For curative treatment to be possible, metastases need to be found while they are small and asymptomatic . The only curative treatment is surgery. Chemotherapeutic treatment is under evaluation, but responses are limited and radiotherapy has no role to play at present.