The incidence of liver cancer and deaths from the disease have doubled since the early 1990s in several high-income countries, including the United States, Canada, Australia, and the United Kingdom.
Liver cancer is the only primary cancer where mortality is increasing in these countries, new findings indicate. "Many of these liver cancers strike people in their 50s when they are still of working age," Morris Sherman, MD, emeritus professor of medicine, University Health Network and the University of Toronto, Ontario, Canada, said in a statement.
"The prospects for surviving liver cancer are bleak, so our only hope is to intervene early and prevent cancer happening in the first place or to find early curable cancers," he added. Data for an age-standardized incidence rate per 100,000 population show that liver cancer rates have increased sharply in all four countries since the early 1990s.
Overall, the highest incidence is in the United Kingdom, at an age-standardized incidence rate of 9.6 per 100,000 in 2015, followed by 9.2 per 100,000 in the United States, 7.4 per 100,000 in Australia, and 6.0 per 100,0000 in Canada.
Deaths from liver cancer have similarly increased among men and women, again based on age-standardized death rates per 100,000 population. In 2014, the age-standardized mortality rate was 8.7 per 100,000 population in the United Kingdom, while in 2015 the age-standardized mortality rate was 6.6 per 100,000 in both the United States and Australia and 7.5 per 100,000 population in Canada.
The surge in Liver Cancer
Sherman told the audience that the reasons for the surge in liver cancer incidence, and the increase in mortality, include infection with hepatitis B and hepatitis C virus, as well as the obesity epidemic.
The obesity epidemic is fueling an epidemic of nonalcoholic fatty liver disease (NAFLD), which can progress to liver cancer, he explained. Even in high-income countries such as the United States, many people are unaware that they have been infected with hepatitis B or C virus; by the time they present with symptoms, it's often too late to offer any curative treatment.
Although new directly acting antiviral drugs (DAA) have transformed the management of hepatitis C effectively curing 95% of all patients who are treated with DAAs the same progress has not been made with hepatitis B. However, there are drugs that can help prevent progression to liver cancer in many patients.
The obesity epidemic that is causing increasing numbers of patients to develop NAFLD is nowhere near under control, Sherman commented. For example, an estimated 20% of the population in developed countries has some level of NAFLD.
Of these, 1 in 10 could progress to cirrhosis, of whom 20% to 30% could develop liver cancer. Indeed, in early June 2018, the Canadian Association for the Study of the Liver published guidelines recommending that individuals born between 1945 and 1975 the baby boomers be tested for hepatitis C.