Liver cancer or hepatocellular carcinoma (HCC) is the sixth most common malignancy (Figure 1) and the fourth leading cause of cancer-related death worldwide (Figure 2).[1] In 2018, the age standardized incidence rates for liver cancer were highest in Eastern Asia and Sub-Saharan Africa, exceeding 14.1 per 100,000 persons, whereas the United States fell into the higher intermediate category with age standard incidence rates between 9.3 to 14.1 per 100,000 persons.[1] This geographic disparity is likely attributable in large part to the higher prevalence of chronic hepatitis B virus (HBV) infection in Asia and Africa. Globally, chronic infection with hepatitis B virus (HBV) is the leading cause of liver cancer. Individuals with chronic HBV infection can carry a 20- to 60-fold increased risk of HCC compared to individuals without HBV infection.[2,3]
In the United States, the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute (NCI) combine liver cancer and intrahepatic bile duct cancer under "liver cancer", but HCC represents 75 to 90% of these total liver malignancies.[4,5]. The annual number and rate of new liver cancer cases has overall increased during the past 18 years corresponding with advancing age of the population, though the pace has slowed since 2014 (Figure 3).[4] In 2016, there was an estimated 33,482 liver and intrahepatic bile duct cancer cases reported in the United States, with expectations for this number to increase to 42,030 new cases in 2019, according to the Surveillance Epidemiology End Result (SEER) program of the NCI.[6]
In 2016, liver cancer was the seventh leading cause of cancer deaths in the United States (Figure 4). The number of liver cancer deaths in the United States has steadily increased from 1999 through 2016, with 26,569 liver cancer deaths in 2016 (Figure 5).[4] For age-adjusted death rates for HCC, there has been an overall 2.1% (95% CI 1.9% to 2.3%) increase in mortality among the United States population from 1999 through 2016 with 80% of the deaths occurring among those older than 55 years with HCC with underlying cirrhosis.[7] In 2016, whites had the highest number of cases, but the lowest incidence rate (per 100,000 persons) (Figure 6).[6] Only the Asian/Pacific Islander population saw a decrease in mortality during this period was among the Asian and Pacific Islanders. Men had much higher incidence than women of HCC in 2016, with an age-specific rate per 100,000 people of 12.6 among men versus 4.5 among women.[6] In the United States, liver cancer is more common in men than women, and among Asian/Pacific Islander and American Indian/Alaska Native populations.[6]