CDC Reports Increasing Incidence of Liver Cancer,

liver411

Mostly Due to Chronic Hepatitis B and C


                               
               

SUMMARY: The number of new cases of hepatocellular carcinoma (HCC), a type of primary liver cancer, has increased in the U.S. over the past several years, reaching an incidence rate of 3.2 cases per 100,000 persons in 2006, according to the latest figures reported by the Centers for Disease Control and Prevention (CDC) in the May 7, 2010 issue of Morbidity and Mortality Weekly Report. Blacks and people in the 50-59 year age group had the largest annual percentage increases in HCC.

               
                               

By Liz Highleyman

Over years or decades, chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection can lead to serious liver disease including cirrhosis and HCC. Liver cancer is the third leading cause of cancer death worldwide and the ninth leading cause in the U.S.

More than three-quarters of all liver cancer cases are thought to be attributable to hepatitis B or C; other causes include heavy alcohol consumption and genetic diseases of the liver. While the incidence of new HBV and HCV infections has declined dramatically, liver cancer rates continue to increase as people infected long ago reach the stage of developing advanced liver disease.

To determine trends in U.S. HCC incidence, CDC researchers analyzed data for 2001-2006 (the most recent available) from CDC's National Program of Cancer Registries and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) system. They compiled reports from 45 cancer registries, covering 90.4% of the U.S. population. Only microscopically confirmed HCC cases were included in the analysis.

Results
        A total of 48,596 new HCC cases were reported during 20011-2006.
        The average annual HCC incidence rate during 2001-2006 was 3.0 per 100,000 persons.
        The incidence rate increased significantly over the study period, from 2.7 per 100,000 persons in 2001 to 3.2 per 100,000 persons in 2006.
        The average annual percentage change (APC) in the HCC incidence rate was 3.5%.
        Men had about 3 times higher risk of developing HCC than women (5.0 vs 1.3 per 100,000 persons), a disparity recently linked to androgen receptors.
        HCC annual incidence rates increased for both men (from 4.5 to 5.4 per 100,000) and women (from 1.2 to 1.4 per 100,000) between 2001 and 2006.
        The median age at HCC diagnosis was 64 years (62 for men, 69 for women).
        The highest HCC incidence rates were seen among people in the 70-79 year age group (13.7 per 100,000 persons), followed by age 80 or older (10.0 per 100,000), 60-69 years (9.6 per 100,000), and 50-59 years (6.8 per 100,000), then dropping in the 40-49 year group (2.1 per 100,000).
        The greatest increase in incidence, however, was in the 50-59 year age group (APC 9.1).
        Asian/Pacific Islanders had the highest HCC incidence rate (7.8 per 100,000 persons) -- reflecting their high hepatitis B prevalence -- followed by Hispanics (5.7 per 100,000), blacks (4.2 per 100,000), American Indian/Alaska Natives (3.2 per 100,000), and whites (2.6 per 100,000).
        The largest increases in HCC incidence were seen among blacks (APC 4.8) and whites (APC 3.8), while it remaining stable among Asians.
        HCC incidence rates varied widely among states, ranging from 1.4 per 100,000 persons in South Dakota to 5.5 per 100,000 in Hawaii.
        States with particularly large annual increases in HCC incidence included Oklahoma (+11.7%), Maine (+9.9%), Iowa (+9.0%), and Georgia (+7.4%).


Graphic caption: Hepatocellular carcinoma incidence rate by sex --
United States, 2001--2006 (Source: CDC).

"The results demonstrate a continuation of long-term increases in HCC incidence and persistent HCC racial/ethnic disparities," the researchers concluded.

"Development of viral hepatitis services, including screening with care referral for persons chronically infected with HBV or HCV, full implementation of vaccine-based strategies to eliminate hepatitis B, and improved public health surveillance are needed to help reverse the trend in HCC," they recommended.

In an editorial note, the authors explained that HCC rates were highest among people born during 1946-1964, particularly so among black men. "In the absence of testing and care," they wrote, "the risk for HCC is expected to increase with aging of the cohort of persons with HCV infection."

Timely treatment for hepatitis B or C reduces the risk of developing liver cancer. People with chronic liver disease should be screened for HCC, since the chances of successful treatment are better when the cancer is detected at an earlier stage.

"Early identification of viral hepatitis with referral to prevention and care services can decrease transmission to others," the authors stated. "Treatment of viral hepatitis is cost-effective, and medical management can decrease morbidity."

A recent report on prevention of hepatitis and liver cancer from the Institute of Medicine called for a national comprehensive approach comprising improved viral hepatitis surveillance, community education, vaccination to eliminate HBV transmission, and development of prevention and health services targeting key populations (i.e., drug users, foreign-born individuals, and HIV positive people), including HBV and HCV screening and linkage to appropriate medical care.

Investigator affiliations: Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention; Division of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health Promotion, CDC.

6/15/10

Reference
S O'Connor, JW Ward, M Watson, and others. Hepatocellular carcinoma -- United States, 2001-2006. Morbidity and Mortality Weekly Report (MMWR). 59(17): 517-520 (Free full text). May 7, 2010.