The incidence of liver cancer in the United States tripled between 1975 and 2005, but survival rates are improving, according to the results of a study published in the Journal of Clinical Oncology.
The liver is the largest organ in the body and is responsible for over 500 functions, including the secretion of glucose, proteins, vitamins, and fats; the production of bile; the processing of hemoglobin; and detoxification of numerous substances. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer (cancer that begins in the liver). Factors that increase the risk of developing HCC include long-term, heavy alcohol use and chronic infection with hepatitis B or C viruses.
Hepatocellular carcinoma is the third leading cause of cancer deaths worldwide. Historically, the rates of HCC incidence have been lower in the United States than in other countries; however, the disease is on the rise, possibly as a result of the increasing incidence of infection with the hepatitis B and C viruses.
In this study, researchers used the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) registries to examine the age-adjusted incidence trends for HCC between 1975 and 2005. They found that the rates of liver cancer tripled from 1.6 cases per 100,000 people to 4.9 per 100,000. Asians and Pacific Islanders had higher incidence and mortality rates than other ethnic groups, possible due to a higher rate of hepatitis B in this group. The period from 2000 to 2005 showed a marked increase in incidence rates among Hispanic, African-American, and White middle-aged men. The researchers speculated that this could be related to an epidemic of hepatitis C during the 1960s, when men in this group were young adults.
One positive trend was improved one- to five-year survival rates between 1992 and 2005, perhaps as a result of earlier diagnosis and treatment. One-year survival rates nearly doubled between 1992 and 2005—from 25% to 47%. Still, the survival rate for this disease is below 50%.
The researchers could not determine why the incidence of HCC is on the rise but speculated that it could be related to the increasing incidence of hepatitis C, a major risk factor for HCC. They concluded: “HCC incidence and mortality rates continue to increase, particularly among middle-aged [African-American], Hispanic, and [W]hite men. Screening of at-risk groups and treatment of localized-stage tumors may contribute to increasing HCC survival rates in the United States. More progress is needed.”
Reference: Altekruse SF, McGlynn KA, Reichman ME. Hepatocellular carcinoma incidence, mortality, and survival trends in the United States from 1975 to 2005. Journal of Clinical Oncology. 2009; 27: 1485-1491.