Onions, grains, seafood reduce liver cancer risk

• Low selenium levels linked to disease development
• Patients taking cholesterol drugs are half as likely to die

A new study, published in The American Journal of Clinical Nutrition, 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.

The research is a joint project involving the International Agency for Research on Cancer (IARC), the Royal College of Surgeons in Ireland (RCSI), Charité Medical School Berlin, and collaborators in the European Prospective Investigation into Cancer and Nutrition (EPIC).

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.

Meanwhile, British scientists claim statins almost halve the odds of dying from cancer. A study of almost 23,000 cancer patients found that those who happened to have high cholesterol were up to 47 per cent less likely to die of the four most common forms of the disease.

The findings first reported by DailyMailUK Online were presented at a European Society of Cardiology conference in Florence over the weekend.Lead researcher of the selenium study, Dr. David Hughes, of the Department of Physiology and Centre for Systems Medicine of the RCSI in Dublin, Ireland, said: “The research findings tentatively suggest that where selenium is suboptimal, increasing selenium intake may be a further strategy for liver cancer prevention in addition to avoiding alcohol consumption, maintaining a healthy body weight, and stopping smoking.

“However, 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.”

The study was based on the EPIC cohort, which is composed of more than half a million participants across 10 European countries, using 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. Blood levels of selenium and selenoprotein P were measured in the study participants by the laboratory of Dr. Lutz Schomburg at Charité Medical School Berlin.

In 2012, worldwide, there are estimated to have been 782 000 new cases of liver cancer. It is the second most common cause of death from cancer worldwide, estimated to have been responsible for nearly 746 000 deaths in 2012 (9.1 per cent of all cancer-related deaths that year). The prognosis for liver cancer is very poor (with an overall ratio of mortality to incidence of 0.95), so the geographical patterns in incidence and mortality are very similar.

“The incidence of liver cancers is increasing in developed countries. 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.”

Meanwhile, researchers are convinced that this was because they were taking statins – which they claim provided a crucial, protective effect against tumour growth.The discovery at Aston University in Birmingham will add to calls for the cholesterol-lowering pills to be routinely used in cancer treatment.

It backs up a slew of recent studies, which have shown that patients taking statins were far less likely to die from the illness.Only last month a team from the Institute of Cancer Research in London found that the pills reduce the risk of breast cancer returning by up to 50 per cent.

And two major American studies last year showed they slashed the risk of dying from cancer by between 22 per cent and 55 per cent, depending on the type of tumour.

Researchers believe that cholesterol in the blood fuels tumour growth, and encourages cancer to spread and return.But as statins reduce cholesterol levels, they help to prevent the cancer becoming far more deadly.

For this latest study, researchers analysed information from 22,677 people suffering from lung, breast, prostate and bowel cancers, taken from a database of nearly one million patients. All had been admitted to hospitals in the United Kingdom (U.K.) with cancer between January 2000 and March 2013, and anonymised information on their other health conditions – including whether they had high cholesterol – was available.

After taking into account other factors which might influence death rates, including age, gender, and ethnicity, researchers found cancer patients were less likely to die early if they had a diagnosis of high cholesterol than if they did not.

The study says statins are associated with a 47 per cent lower risk of death from prostate cancer, a 43 per cent lower risk in those with breast cancer, a 30 per cent lower risk in bowel cancer cases, and a 22 per cent lower risk in lung cancer patients.Some nine out of ten of the patients who had been diagnosed with high cholesterol were on statins.