Status quo of chronic liver diseases, including hepatocellular carcinoma, in Mongolia

Abstract

Because Mongolia has much higher liver disease burden than any other regions of the world, it is necessary to provide information on real-time situation of chronic liver disease in Mongolia. In this article, we reviewed studies performed in Mongolia from 2000 to 2011 on seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) among healthy individuals and patients with chronic liver diseases, and on the practice patterns for the management of liver cirrhosis and hepatocellular carcinoma (HCC). According to previous reports, the seroprevalence of HBV and HCV in general population in Mongolia is very high (11.8% and 15% for HBV and HCV, respectively). Liver cirrhosis is also highly prevalent, and mortality from liver cirrhosis remained high for the past decade (about 30 deaths per 100,000 populations per year). Among patients with cirrhosis, 40% and 39% are positive for HBsAg and anti-HCV, respectively, and 20% are positive for both. The seroprevalence is similar for HCC and more than 90% of HCC patients are positive for either HBV or HCV. The incidence of HCC in Mongolia is currently among the highest in the world. The mortality from HCC is also very high (52.2 deaths per 100,000 persons per year in 2010). Partly due to the lack of established surveillance systems, most cases of HCC are diagnosed at an advanced stage. The mortality from liver cirrhosis and HCC in Mongolia may be reduced by implementation of antiviral therapy program and control of alcohol consumption.

Keywords: Carcinoma, hepatocellular; Liver cirrhosis; Mongolia.

Figure 1

Incidence of liver cancer per 100,000 population as of 2009 (Ministry of Health, Mongolia). Blue area indicates areas of high prevalence, light blue moderate prevalence, and white-blue low prevalence.

Figure 2

Liver cirrhosis-related deaths in Mongolia. Deaths due to liver cirrhosis during 2006-2010 are shown. Mortality from liver cirrhosis has been persistently high in the last 5 years.

Figure 3

Viral causes of liver cirrhosis. Seroprevalence of hepatitis B virus surface antigen (HBsAg) and anti-HCV in patients with cirrhosis in Mongolia, 2000-2009. Anti-HCV, antibodies against hepatitis C virus; Anti-HCV+, seropositive for anti-HCV only; Dual+, seropositive for both HBsAg and anti-HCV; HBsAg+, seropositive for HBsAg only.

Figure 4

Increase in the incidence of hepatocellular carcinoma (HCC) in comparison with other cancers. Prevalence of HCC among different cancers (%) during three periods since 1975.

Figure 5

Incidence of hepatocellular carcinoma (HCC) since 1967. The increase in HCC cases over time in Mongolia (per 100,000 population) is shown.

Figure 6

Age-adjusted incidence of hepatocellular carcinoma (HCC) in the Asia-Pacific region. Mongolia has the world's highest incidence of liver cancer, which is six times the global average and increasing.

Figure 7

Management of hepatocellular carcinoma (HCC). According to National Cancer Center statistics, only 16% of patients with HCC are eligible for hepatoectomy, 29% are eligible for less-invasive procedures such as transarterial chemoembolization (TACE) or radio frequency ablation (RFA), whereas 55% are not eligible for any treatment.

Figure 8

Shift in surgical method has resulted in few right hepatectomies. With implementation of the Glissonian technique in 2008 performance of major right liver resections is unnecessary in those patients whose cancers are located only in segments 5 and 8, and it is possible to preserve the anterior segment, which represents 33-35% of the liver, instead of removing 63-65%.

Figure 9

Survival rates of two surgical methods. The post-surgical survival rate (> 6 months) was 80.76% in patients who underwent the Glissonian approach, compared to 69.23% in patients who had conventional liver resection.