Scientists at MD Anderson and in Taiwan conducted a massive prospective analysis of comprehensive medical, demographic and lifestyle data from 428,584 people in Taiwan from 1994 to 2008.
"These two enzymes alone predicted 91 percent of liver cancer cases in our prospective study," said senior author Xifeng Wu, M.D., Ph.D., professor and chair of MD Anderson's Department of Epidemiology. "If our research is confirmed in other studies, we'd have a measure for liver cancer risk that's easy to apply via a simple blood test that's already in widespread clinical use."
While hepatitis B and C infection are risk predictors for those considered at high likelihood to develop liver cancer, in this study of a general population, levels of two enzymes emerged as unsurpassed predictors of risk.
Between 30 and 40 percent of people who develop liver cancer are not infected with either virus. There has been no way to assess their risk, Wu noted.
their risk would allow people to respond with lifestyle changes to address
other risk factors, such as stopping smoking, reducing alcohol consumption,
engaging in physical activity and better managing diabetes," Wu said.
The study is a collaboration with MJ Health Management, the largest private health-screening company in Asia, the Institute of Population Science of the National Health Research Institutes of Taiwan, and China Medical University Hospital.
The researchers developed five models of risk prediction, and the best predictor consisted solely of levels of the enzymes alanine transaminase
(ALT) and aspartate transaminase (AST). Adding other factors to the 91.2% prediction rate of the enzymes only raised the rate to 94 percent. Transaminases are involved in production of amino acids and at elevated levels are signs of liver damage.
"We think our models will apply generally, but validation studies must be conducted in other populations," Wu said. Future plans include putting the risk models on a website for public use.
According to the National Cancer Institute, an estimated 28,750 new cases of liver cancer will be diagnosed in 2012 and 20,550 people will die from the disease. Five-year survival rates for liver cancer patients range from:
- 27.7 percent of those with disease limited to the liver upon diagnosis;
- 10 percent of those whose disease has spread to lymph nodes; and
- only 2.1 percent of those with disease that has spread to other organs.
Worldwide, an estimated 749,000 cases were diagnosed in
2008, the latest year available, and 695,000 people died, according to the
International Agency for Research on Cancer. Countries in Asia, Africa and
Southern Europe have the highest incidence of the disease.
The study was funded by grants
from the MD Anderson Center for Translational and Public Health Genomics of the
Duncan Family Institute for Cancer Prevention and Risk Assessment, MD Anderson Cancer Center Trust, and the Taiwan Department
of Health Clinical Trial and Research Center of Excellence.
Paper in the Journal of the National Cancer Institute
MD Anderson news release.