Poor oral health raises liver cancer risk by 75%

*One in three people globally do not have access to safe drinking water, say UNICEF, WHO

Poor oral health is associated with a 75 per cent increased risk of hepatocellular carcinoma (HCC), the most common form of liver cancer, new research has found.

The study, by researchers at Queen’s University Belfast, analysed a large cohort of over 469,000 people in the United Kingdom (UK), investigated the association between oral health conditions and the risk of a number of gastrointestinal cancers, including liver, colon, rectum and pancreatic cancer. Models were applied to estimate the relationship between cancer risk and self-reported oral health conditions, such as painful or bleeding gums, mouth ulcers and loose teeth.

Whilst no significant associations were observed on the risk of the majority gastrointestinal cancers and poor oral health, a substantial link was found for hepatobiliary cancer.

“Poor oral health has been associated with the risk of several chronic diseases, such as heart disease, stroke and diabetes,” explained Dr. Haydée WT Jordão, from the Centre of Public Health at Queen’s University Belfast and lead author of the study. “However, there is inconsistent evidence on the association between poor oral health and specific types of gastrointestinal cancers, which is what our research aimed to examine.”

Of the 469,628 participants, 4,069 developed gastrointestinal cancer during the (average) six-year follow up. In 13 per cent of these cases, patients reported poor oral health. Participants with poor oral health were more likely to be younger, female, living in deprived socioeconomic areas and consumed less than two portions of fruit and vegetables per day.

The biological mechanisms by which poor oral health may be more strongly associated with liver cancer, rather than other digestive cancers, is currently uncertain. One explanation is the potential role of the oral and gut microbiome in disease development. “The liver contributes to the elimination of bacteria from the human body,” stated Dr Haydée WT Jordão. “When the liver is affected by diseases, such as hepatitis, cirrhosis or cancer, its function will decline and bacteria will survive for longer and therefore have the potential to cause more harm. One bacteria, Fusobacterium nucleatum, originates in the oral cavity but its role in liver cancer is unclear. Further studies investigating the microbiome and liver cancer are therefore warranted.”

Another theory in explaining the higher cancer risk due to poor oral health suggests that participants with a high number of missing teeth may alter their diet, consuming softer and potentially less nutritious foods, which in turn influence the risk of liver cancer.

Liver cancer is the sixth bigger cancer killer in the EU, claiming the lives of almost 60,000 people per year. The five-year survival rate for the disease across Europe is just 11 per cent and approximately nine in 10 cases are in individuals over the age of 55 ref media pack. It is believed that up to half of cases of liver cancer are preventable, with risk factors often relating to lifestyle, such as overweight or obesity, smoking and alcohol consumption.

Meanwhile, new report on inequalities in access to water, sanitation and hygiene also reveals more than half of the world does not have access to safe sanitation services.

According to a new report by the United Nations Children Fund (UNICEF) and the World Health Organisation (WHO), billions of people around the world are continuing to suffer from poor access to water, sanitation and hygiene. Some 2.2 billion people around the world do not have safely managed drinking water services, 4.2 billion people do not have safely managed sanitation services, and 3 billion lack basic handwashing facilities.

The Joint Monitoring Programme report, Progress on drinking water, sanitation and hygiene: 2000-2017: Special focus on inequalities finds that, while significant progress has been made toward achieving universal access to basic water, sanitation and hygiene, there are huge gaps in the quality of services provided.

“Mere access is not enough. If the water isn’t clean, is not safe to drink or is far away, and if toilet access is unsafe or limited, then we’re not delivering for the world’s children,” said Kelly Ann Naylor, Associate Director of Water, Sanitation and Hygiene, UNICEF. “Children and their families in poor and rural communities are most at risk of being left behind. Governments must invest in their communities if we are going to bridge these economic and geographic divides and deliver this essential human right.”

The report reveals that 1.8 billion people have gained access to basic drinking water services since 2000, but there are vast inequalities in the accessibility, availability and quality of these services. It is estimated that 1 in 10 people (785 million) still lack basic services, including the 144 million who drink untreated surface water. The data shows that eight in 10 people living in rural areas lacked access to these services and in one in four countries with estimates for different wealth groups, coverage of basic services among the richest was at least twice as high as among the poorest.

“Countries must double their efforts on sanitation or we will not reach universal access by 2030,” said Dr. Maria Neira, WHO Director, Department of Public Health, Environmental and Social Determinants of Health. “If countries fail to step up efforts on sanitation, safe water and hygiene, we will continue to live with diseases that should have been long ago consigned to the history books: diseases like diarrhoea, cholera, typhoid, hepatitis A and neglected tropical diseases including trachoma, intestinal worms and schistosomiasis. Investing in water, sanitation and hygiene is cost-effective and good for society in so many ways. It is an essential foundation for good health.”

The report also says that 2.1 billion people have gained access to basic sanitation services since 2000 but in many parts of the world the wastes produced are not safely managed. It also reveals that two billion people still lack basic sanitation, among whom seven out of 10 live in rural areas and one third live in the Least Developed Countries.

Since 2000, the proportion of the population practicing open defecation has been halved, from 21 per cent to nine per cent, and 23 countries have achieved near elimination, meaning less than one per cent of the population is practicing open defecation. Yet, 673 million people still practice open defecation, and they are increasingly concentrated in ‘high burden’ countries. Worse, in 39 countries, the number of people practicing open defecation actually increased, the majority of which are in sub-Saharan Africa where many countries have experienced strong population growth over this period.

Finally, the report highlights new data showing three billion people lack basic handwashing facilities with soap and water at home in 2017. It also shows that nearly three quarters of the population of the Least Developed Countries did not have basic handwashing facilities. Every year, 297 000 children under 5 years die due to diarrhea linked to inadequate WASH. Poor sanitation and contaminated water are also linked to transmission of diseases such as cholera, dysentery, hepatitis A, and typhoid.

“Closing inequality gaps in the accessibility, quality and availability of water, sanitation and hygiene should be at the heart of government funding and planning strategies. To relent on investment plans for universal coverage is to undermine decades worth of progress at the expense of coming generations,” said Kelly Ann Naylor.