A group of clinicians and geochemists are working to develop a test for the most common form of primary liver cancer, HCC (Hepatocellular Carcinoma). HCC kills over 600,000 people worldwide every year. It usually develops from chronic liver disease such as hepatitis or cirrhosis, but there is no good biochemical test to indicate when the cancer develops, meaning that even for patients most at risk, it is nearly impossible to know when a cancer may develop until symptoms appear. Now a multi-national group of scientists are developing a new test for HCC, based on methods used to measure the stable isotope compositions of rocks and minerals.
Elements in nature tend to have different isotopes (the same number of protons, but different numbers of neutrons). So for example, in nature, 99% of the carbon is stable carbon-12, 1% is stable carbon-13, and radioactive carbon-14 occurs in trace amounts. This distribution of stable isotopes also occurs with other elements, such as copper and sulphur.
It has been known for some time that in cancer, the body’s copper regulation can be affected. The researchers decided to look at whether the ratios of different copper isotopes varied between HCC patients and normal controls. They compared 23 male HCC patients with 20 controls; they found that the blood of patients with liver cancer had an enriched quantity of certain isotopes in comparison to control patients.
Comparing copper isotopes Cu and Cu, they found that HCC patients have around 0.4 parts per thousand more Cu relative to Cu than the control patients. This difference was also seen with the Sulphur isotopes S and S, with blood of patients with HCC is around 1.5 parts per thousand richer in S relative to S than is normally found.
Group leader, geochemist Vincent Balter (Lyon, France) said
“The findings are interesting and potentially significant. We found that the ratio of Cu to Cu was higher in the blood of cancer patients than in the blood of controls. Preliminary results seem to show that these ratios are in fact reversed in the tumours themselves, which implies that there is a partition of isotopes between the blood and the tumour.
This opens the way for a blood test. At the moment the results are preliminary, but if we can confirm the validity of an isotopic test for HCC, this might have a significant impact on patients who have chronic liver disease, who risk developing liver cancer”.