TCGA's Study of Hepatocellular Carcinoma
What is hepatocellular carcinoma?
Hepatocellular carcinoma is the most common form of liver cancer in the United States, making up more than 80% of cases.1 This disease arises in the hepatocytes, the cells that make up most of the liver.1 Worldwide, this cancer is the third leading cause of cancer-related deaths, but in the United States, it ranks at ninth.2
On a global scale, 78% of liver cancer cases are secondary to chronic Hepatitis B or C infections.2 Another risk factor is cirrhosis, a chronic disease where scar tissue replaces liver cells.1 An estimated 28,720 new cases were diagnosed in the Unites States in 2012.1 View additional information on liver cancer.
What have TCGA researchers learned about hepatocellular cancer?
- An analysis of 196 hepatocellular carcinoma cases confirmed frequent mutations in:
- The TERT promotor region, associated with regulating cell survival
- TP53, one of the most frequently mutated genes in cancer
- CTNNB1, a member of the Wnt signaling pathway that mediates cell growth and differentiation
- Genetic alterations in hepatocellular carcinoma may be targeted by therapies that are currently available or under development:
- Mutations of the TERT promotor, found in 44% of the cancers studied, may be targeted with telomerase inhibitors that are under development.
- In many tumors, TP53 was not genetically altered but inhibited by expression of MDM4, which in turn may be inhibited by investigational drugs.
- 20% of tumors studied showed elevated expression of immune evasion genes, suggesting that this subset may be sensitive to immunotherapies that strengthen the immune system’s surveillance.
1American Cancer Society. Cancer Facts and Figures 2012. Atlanta: American Cancer Society, Inc. 2012.
2Centers for Disease Control and Prevention. Hepatocellular Carcinoma—United States, 2001–2006. Morbidity and Mortality Weekly Report. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5917a3.htm Accessed May 2010.