The hepatitis C virus, a leading cause of liver cancer, under a transmission electron micrograph
Liver cancer stands apart from most other common cancers in that its major causes are well understood. A large proportion of cases are caused by hepatitis B or hepatitis C infection or excessive alcohol intake – meaning that many, if not most, cases of the disease could be prevented. Over the last two decades, the introduction of widespread hepatitis B vaccination programs, together with advances in screening and treatment for both hepatitis B and C, are estimated to have prevented thousands of new liver cancer cases in the United States.
Nevertheless, two major challenges remain:
U.S. liver cancer incidence is on the rise due to a "silent" epidemic of undiagnosed hepatitis C infections, along with growing rates of obesity and diabetes. Outside of the United States, the burden of liver cancer is far larger and growing, due to higher prevalence of hepatitis B and C.
While important advances have been achieved in surgery, certain drug therapies, and in managing the complications of the disease, liver cancer remains notoriously difficult to treat. Few therapies offer cures, and treatments often extend survival by just several months.
The introduction of the first molecularly targeted drug for liver cancer, sorafenib (Nexavar), in 2008 marked an important first chapter in what is expected to be a new era of liver cancer research and treatments. Researchers are hopeful that growing understanding of how liver cancer develops and grows will drive development of more targeted drugs that capitalize on the molecular vulnerabilities of liver cancer cells.