DNA biomarker pinpoints hep B liver cancers

Long-term hepatitis B infection is behind around 80% of cases of primary liver cancer, a disease with only a 10% chance of survival at 5 years. Having a blood-based biomarker could give physicians a non-invasive way to pick out those people most likely to progress from infection to cancer, as well as see who would most benefit from treatment. According to research presented at a U.S. cancer meeting, telomere length might be a place to start.

The telomeres are repeated sequences at the ends of the chromosomes that act as caps and protect the chromosomes from damage when cells replicate. As cells age, the telomeres naturally shorten. Once they reach a critical length, the cells die. In cancer, the telomeres can remain intact or even lengthen, and a research team at Kimmel Cancer Center at Jefferson decided to see whether the length of the telomeres could be used as a prognostic blood-based biomarker in hepatitis B virus-related non-cirrhotic hepatocellular carcinoma.

The researchers measured the lengths of telomeres in DNA circulating in the plasma in Korean Americans testing positive for the hepatitis B virus, either with or without liver cancer. This particular ethnic group has disproportionately high levels of hepatitis B infection, often infected at birth or in childhood.

The telomeres were about 50% longer in males with hepatitis B virus-related liver cancer and without cirrhosis, compared with those in cancer-free people with hepatitis B infection. Longer telomeres also suggested an increased risk of developing hepatitis B-related liver cirrhosis.

"This is the first study to demonstrate that relative telomere length in circulating cell-free serum DNA could potentially be used as a simple, inexpensive and non-invasive biomarker for HCC risk," said Hushan Yang of the Division of Population Science at the Department of Medical Oncology at Thomas Jefferson University and Jefferson's Kimmel Cancer Center. "This sets the stage for further retrospective and prospective investigations, in-depth molecular characterizations, and other assessments to determine the clinical value of serum DNA telomere length in risk prediction and early detection of HCC."

These results were presented at the American Association for Cancer Research (AACR) Annual Meeting 2012 in Chicago.

- read the press release
- see the abstract