Hepatic adenoma that does not cause physical symptoms, referred to as asymptomatic hepatic adenoma, require little more than watchful waiting and diagnostic testing such as imaging studies to rule out the progression of the adenoma. These imaging studies will monitor any growth or changes of the adenoma to rule out its progression. If the hepatic adenoma has ruptured and is causing liver bleeding, then a surgeon might excise the tumor from the liver to prevent further problems.
While a hepatic adenoma does not cause disease, physicians recognize that there is some risk of benign adenoma undergoing changes that might result in a malignancy in the liver. These malignancies, called hepatocellular carcinoma (HCC), are a deadly form of cancer that can necessitate extreme medical measures to prevent the spread of disease. Not all hepatic adenoma will undergo this transformation, however, and physicians feel it would be inappropriate to treat all adenoma patients with an aggressive hand. To identify which hepatic adenoma may transform into HCC, doctors now use an innovative genetic grading system to determine risk.
(Image from: Pathogenesis of human hepatocellular carcinoma)
Genetic Basis of Hepatic Adenoma
Doctors use genetic testing to determine the risk of hepatic adenoma transforming into HCC in one of two ways. First, the adenoma is genetically tested to see if it cells’ nuclei have a certain protein in them that causes other types of liver cancers: HCC and hepatoblastoma. The beta-catenin gene, also called CTNNB1, makes the protein called beta-catenin, which is an important part of normal body function. Inside some hepatic adenoma, however, beta-catenin can move into the nucleus of the cells and cause excessive DNA replication to occur leading to abnormal growth and potentially HCC. The presence of beta-catenin in the hepatic adenoma’s nucleus indicates that it may be shifting into a malignancy.
The second approach to genetic testing as a means to determine whether or not hepatic adenoma is likely to transform is to test the entire individual’s genome for any mutated genes. Specifically, individuals whose genome contains a mutation at the hepatocyte nuclear factor-1a gene (HNF1a) and/or the TCF1 gene can sometimes have transformation of the benign adenoma into carcinoma. These genes are responsible for how liver cells divide. If they are mutated, liver cancer can result. Up to 50% of individuals with a mutated TCF1 gene have hepatic adenoma that will undergo transformation into hepatocellular carcinoma.
Using Genetic Screening to Diagnose
With the advent of new genetic testing for individuals with hepatic adenoma, doctors are able to more readily predict if a patient’s benign adenoma is likely to develop into HCC. This allows the physician to tailor his or her approach with delicacy and only pursue aggressive treatment for those individuals likely to have their adenoma progress into HCC. Genetic testing for individuals with hepatic adenoma is a remarkable new approach to identification and treatment and has the potential to save many lives. As genetic testing becomes more commonplace, barriers to providing this testing will be reduced and more physicians will likely use this technology to help their patients better understand their course of disease.