MedicalResearch.com Interview with:
Dr. David Hughes
Honorary Lecturer, Centre for Systems Medicine
RCSI Physiology & Medical Physics Dept
Royal College of Surgeons in Ireland
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Liver cancer is the second most common cause of death from cancer worldwide, and the seventh most common cause of death from cancer in Europe (1).
“The incidence of liver cancers is increasing in developed countries, likely due to Western lifestyle and dietary habits. Liver cancers are often diagnosed at late stages and have limited treatment options,” says IARC scientist Dr Mazda Jenab, one of the study’s authors. “Further research is needed into the modifiable determinants of these cancers and effective prevention strategies.”
A growing body of evidence suggests that suboptimal intakes of the micronutrient selenium contribute to the development of several cancers (2). Selenium is a trace mineral micronutrient that is found in foods like shellfish, salmon, Brazil nuts, meat, eggs, grains, and onions. However, selenium levels in foods depend largely on the levels of selenium in the soil where the food is grown and animals graze. Soil levels tend to be low in many regions in Europe, contributing to lower body levels of selenium in those populations compared with people living in regions with higher soil selenium concentrations, such as North America. In humans, selenium is essential, particularly for the effective functioning of the immune system and in controlling oxidative processes linked to cancer development.
This new study shows that the highest levels of blood selenium or of selenoprotein P, the protein that distributes selenium from the liver around the body, are associated with a decreased risk of developing liver cancer (particularly hepatocellular carcinoma), even when all other major liver cancer risk factors are taken into account. The study also shows that selenium level is not associated with the development of gall bladder or biliary tract tumours (3).
The study was based on the European Prospective Investigation of Cancer and Nutrition (EPIC) cohort, headed by the International Agency for Research on Cancer (IARC) in Lyon, France, and composed of more than half a million participants across 10 European countries. We used a case–control design of 121 liver cancers and 140 gall bladder and biliary tract cancers matched to equal numbers of individuals free of cancer within the cohort.
MedicalResearch.com: What should readers take away from your report?
Response: The research findings tentatively suggest that where selenium is suboptimal, such as for most people in Europe, increasing selenium intake may be a further strategy for liver cancer prevention in addition to moderating or avoiding alcohol consumption, maintaining a healthy body weight, and stopping smoking.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Response: It is important to stress that this is based on a single study with a modest number of liver cancers, and thus our results need to be validated by further studies before any public health recommendations can be made. For example, randomised controlled trials in populations where selenium is suboptimal (e.g. Western Europe) are needed to test whether increasing selenium intake may reduce the risk of liver cancer, especially for those at high risk (e.g. hepatitis B and C virus positive, or presence of liver damage / cirrhosis ) for these cancers.
MedicalResearch.com: Is there anything else you would like to add?
Response: The results also suggest that there is a larger risk for developing hepatocellular carcinoma among overweight and obese participants with low amounts of selenoprotein P, further underlining the importance of maintaining a healthy body weight.
Note: The study was jointly funded by the French National Cancer Institute (Institut National du Cancer; INCa) and the Health Research Board of Ireland (HRB).
MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.
1. Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, et al. (2013). GLOBOCAN 2012 v1.0, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 11 [Internet]. Lyon, France: International Agency for Research on Cancer. Available from: http://globocan.iarc.fr.
2. Méplan C, Hesketh J. Selenium and cancer: a story that should not be forgotten-insights from genomics. Cancer Treat Res. 2014;159:145–66.
3. Hughes DJ, Duarte-Salles T, Hybsier S, Trichopoulou A, Stepien M, Aleksandrova K, et al. (2016). Prediagnostic selenium status and hepatobiliary cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort. Am J Clin Nutr. Available from: http://dx.doi.org/10.3945/ajcn.116.131672.
Prediagnostic selenium status and hepatobiliary cancer risk in the European Prospective Investigation into Cancer and Nutrition cohortAm J Clin Nutr ajcn131672; First published online June 29, 2016.doi:10.3945/ajcn.116.131672
David J Hughes, et al
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