Routine Blood Tests Gauge Liver Cancer Risk

Enzyme levels in the blood routinely monitored by physicians as liver function indicators are also the best predictor of liver cancer risk.

Elevated levels of two enzymes, alanine transaminase (ALT) and aspartate transaminase (AST), which are involved in producing amino acids, are an indicator of liver damage.

A team of scientists at the National Health Research Institutes (Taipei, Taiwan) and the MD Anderson Cancer Center (Houston, TX, USA) carried out a prospective study evaluating comprehensive medical, demographic and lifestyle data from 428,584 people in Taiwan from 1994 to 2008, with average follow-up of 8.5 years.

The researchers divided study participants into two groups: the 130,533 who had known Hepatitis C (HCV) test results and the other 298,051. They found 1,668 cases of liver cancer. The researchers developed their risk prediction models by dividing each cohort in half, which allowed them to base the model on one set and then validate the model in the second set. Five models were analyzed: health history alone, transaminase enzymes alone, health history plus transaminases, and a model that added Hepatitis B (HBV) status and alpha-fetoprotein levels to the third model. The fifth model added HCV, including all five factors.

The model that relied only on levels of the enzymes alanine transaminase (ALT) and aspartate transaminase (AST) predicted 91.2% of cancer cases. The scientists found that levels of ALT or AST at or above 25 international units per liter (IU/L) of blood were predictive of cancer risk. This is less than the 40 IU/L commonly defined as the upper limit of normal levels. A person with HBV, but with abnormal transaminase, had a probability of 38.2% of having liver cancer in 10 years. A person with HBV and normal transaminases would have only a 0.3% risk at 10 years if other risk factors were equal to the first person.

Xifeng Wu, MD, PhD, the senior author of the study, said, "These two enzymes alone predicted 91% of liver cancer cases in our prospective study. If our results are 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.” The study was published on October 16, 2012, in the Journal of the National Cancer Institute.

Related Links:
Taiwanese National Health Research Institutes
MD Anderson Cancer Center