Sun exposure and vitamin D status may have independent roles in the risk of CNS demyelination. Both will need to be evaluated in clinical trials for multiple sclerosis prevention.

Primary liver cancer, the major histology of which is hepatocellular carcinoma (HCC), is the second leading cause of cancer death worldwide. We comprehensively examined recent international trends of primary liver cancer and HCC incidence using population-based cancer registry data. Incidence for all primary liver cancer and for HCC by calendar time and birth cohort was examined for selected countries between 1978 and 2012. For each successive 5-year period, age-standardized incidence rates were calculated from Volumes V to XI of the Cancer Incidence in Five Continents (CI5) series using the online electronic databases, CI5plus. Large variations persist in liver cancer incidence globally. Rates of liver cancer remain highest in Asian countries, specifically in the East and South-East, and Italy. However, rates in these high-risk countries have been decreasing in recent years. Rates in India and in most countries of Europe, the Americas and Oceania are rising. As the population seroprevalence of hepatitis B virus (HBV) continues to decline, we anticipate rates of HCC in many high-risk countries will continue to decrease. Treatment of hepatitis C virus (HCV) is likely to bring down rates further in some high-rate, as well as low-rate, countries with access to effective therapies. However, such gains in the control of liver cancer are at risk of being reversed by the growing obesity and diabetes epidemics, suggesting diabetes treatment and primary prevention of obesity will be key in reducing liver cancer in the longer-term.Additional Supporting Information may be found in the online version of this article.

Primary liver cancer, the most common histologic types of which are hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), is the second leading cause of cancer death worldwide. While rising incidence of liver cancer in low-risk areas and decreasing incidence in some high-risk areas has been reported, trends have not been thoroughly explored by country or by histologic type. We examined liver cancer incidence overall and by histology by calendar time and birth cohort for selected countries between 1978 and 2007. For each successive 5-year period, age-standardized incidence rates were calculated from volumes V-IX of the Cancer Incidence in Five Continents electronic database (CI5plus) and the newly released CI5X (volume X) database. Wide global variations persist in liver cancer incidence. Rates of liver cancer remain highest in Asian countries, specifically Eastern and South-Eastern Asian countries. While rates in most of these high-risk countries have been decreasing in recent years, rates in India and several low-risk countries of Africa, Europe, the Americas, and Oceania have been on the rise. Liver cancer rates by histologic type tend to convey a similar temporal profile. However, in Thailand, France, and Italy, ICC rates have increased while HCC rates have declined. We expect rates in high-risk countries to continue to decrease, as the population seroprevalence of hepatitis B virus (HBV) continues to decline. In low-risk countries, targeted screening and treatment of the hepatitis C virus (HCV), treatment of diabetes and primary prevention of obesity, will be key in reducing future liver cancer incidence.

Our reporting of a projected increase in PLC incidence to 2030 in 30 countries serves as a baseline for anticipated declines in the longer term through the control of hepatitis B virus and hepatitis C virus infections by vaccination and treatment; however, the prospect that rising levels of obesity and its metabolic complications may lead to an increased risk of PLC that potentially offsets these gains is a concern. (Hepatology 2017).