LIVER CANCER – HEPATOCELLULAR CARCINOMA (HCC – ALSO KNOWN AS HEPATOMA)
The primary treatment for hepatocellular carcinoma (HCC – also known as hepatoma) is surgical removal, often by means of a complete liver removal and liver transplantation from an unrelated donor. Surgical removal has curative potential, particularly for patients with localized disease who do not have to wait too long for their donated liver.Unfortunately only a minority of HCC patients are candidates for hepatectomy and liver transplantation, and to make matters worse, even those who are eligible may progress to inoperability, while they wait for a donated liver to become available, as the waiting time may exceed a year.
To address the potential for tumor progression and mortality caused by delayed transplantation in otherwise operable patients, “bridge” therapies such as radiofrequency ablation or chemoembolization, even though not typically regarded as curative, have been applied as a means to delay tumor progression until removal of the malignant liver and transplantation may occur.
In patients where surgical removal is not possible, HCC patients have received modest life extension from the nonsurgical ablative therapies and local radiotherapy. High dose radiotherapy has created prolonged responses and some long term disease-free survivals in HCC patients, though relapse at the treated site remains common due to the often limited dose of radiation that may be safely applied, leaving room for further improvement.
LIVER METASTASES
Many cancers metastasize to the liver, from virtually all primary sites in the body, particularly those of gastrointestinal tract origin. While metastatic disease in the liver may represent an incurable situation, there are exceptions. For example, surgical removal of liver metastases from colorectal primary sites has produced reported 5-year survival rates as high as 58% in the MD Anderson Hospital surgical series, with long term survival seen in patients with greater than 3 lesions as well as those with more limited disease, as long as all metastatic disease is removed.
Other ablative therapies including radiofrequency ablation (heating the tumor) and cryotherapy (freezing the tumor) have also produced extended survival in some patients with liver metastases, but compared with surgical removal, the 5-year disease free survival rate appears lower and the tumor recurrence rate in the liver appears higher. Scientifically rigorous comparison of surgical removal versus non-surgical ablative therapies has not been reported.
PRIMARY MALIGNANT BILE DUCT/GALLBLADDER TUMORS (CHOLANGIOCARCINOMA)
Primary malignant bile duct or gall bladder tumors are rare compared with primary hepatocellular carcinoma or liver metastases. Surgical removal represents the treatment of choice but unfortunately, many of these tumors invade liver tissue or other regional structures rendering them inoperable.
External beam radiotherapy with chemotherapy may have a beneficial effect following surgical removal, and appears to have tumor suppressive activity against inoperable tumors, though unfortunately, local recurrence is the rule and cure in non-surgical patients is rare.