Cancer Is Falling Overall But Liver Cancer Is Rising, Largely Due to Hepatitis B and C

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Overall cancer rates have declined significantly in the U.S. over the past decade thanks to better screening and prevention, with the notable exception of liver cancer, according to a new Annual Report to the Nation on the Status of Cancer. A majority of liver cancer is caused by hepatitis B virus (HBV), which is preventable with a vaccine, or hepatitis C virus (HCV), which can now be cured in most cases.

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The annual report, published in the March 9 online edition of the journal Cancer, is the result of a collaboration between the Centers for Disease Control and Prevention (CDC), the National Cancer Institute, the American Cancer Society, and the North American Association of Central Cancer Registries.

Death rates for all cancers combined, and for many specific cancer types, declined among both men and women and in all racial and ethnic groups, according to the report. The overall cancer mortality rate for both sexes combined fell by 1.5% per year from 2003 to 2012. The overall rate of cancer incidence, or new cases, decreased by 1.4% per year among men during this period, with the steepest decline seen for prostate cancer (by 6.6% per year). Overall cancer incidence remained stable among women during this period; cervical and ovarian cancer rates fell, while breast cancer stayed about the same.

The ongoing drop in cancer incidence is due, in large part, to progress in prevention and early detection, while fewer deaths from cancer may also reflect better treatments, according to the CDC. Tobacco control and smoking cessation efforts have contributed to lower rates of lung cancer -- the leading cause of cancer death for both men and women -- and several other types.

But deaths due to liver cancer rose at the fastest rate of all cancers among both and men and women -- by 56% between 2003 and 2012 -- and liver cancer incidence increased more sharply than any other type except thyroid cancer.

From 2003 to 2012 liver cancer mortality increased by an average of 2.8% per year among men and by 2.2% per year among women. During this period liver cancer incidence rose by an average of 3.4% per year among men and by 2.4% among women.

Liver cancer mortality was highest in the 1945-1965 birth cohort -- corresponding to the group at greatest risk for hepatitis C. About twice as many men as women were diagnosed with liver cancer across racial and ethnic groups. Liver cancer incidence was highest among American Indian/Alaska Native men and Asian/Pacific Islander men -- groups with high hepatitis B prevalence.

"The latest data show many cancer prevention programs are working and saving lives," said CDC director Tom Frieden. "But the growing burden of liver cancer is troublesome. We need to do more work promoting hepatitis testing, treatment, and vaccination."

Hepatitis B and C are often asymptomatic during early stages, but over years or decades chronic infection can lead to serious liver damage including cirrhosis (scarring), hepatocellular carcinoma (a type of primary liver cancer), and end-stage liver failure requiring a transplant.

Hepatitis B can be prevented by an effective vaccine that is now part of the routine childhood vaccination series in the U.S. and recommended for others at risk including people living with HIV, people who inject drugs, gay men, people who travel to countries where HBV is endemic, and health workers who could be exposed on the job. Hepatitis B can be treated with antiviral drugs such as tenofovir (Viread) and entecavir (Baraclude), but these usually do not produce a cure and may need to be taken long-term.

There is currently no vaccine for hepatitis C. However, new direct-acting antivirals used in interferon-free regimens can cure more than 90% of people with hepatitis C, and new therapies that are more effective against multiple HCV genotypes are expected soon. Treatment typically lasts 8 to 12 weeks and is well-tolerated, unlike the older interferon-based therapy. CDC estimates that at least half of the 3.5 million people living with hepatitis C in the U.S. do not know they are infected, and recommends that everyone born between 1945 and 1965 be tested at least once for HCV. Hepatitis C incidence has also risen recently in many parts of the country among younger people who inject drugs.

Treatment for hepatitis B and C has been shown to reduce the likelihood of developing liver cancer by up to 75% or 80%, but the risk does not fall back to the level of people who were never infected, so ongoing liver cancer screening is recommended.

Obesity and type 2 diabetes -- associated with fatty liver disease or steatohepatitis -- and heavy alcohol use also contribute to cirrhosis and liver cancer, and experts predict that obesity-associated liver disease is likely to increase in the coming years even as widespread vaccination and antiviral treatment reduce the number of cases attributable to hepatitis B and C.

"[W]hile we are making substantial progress against cancer overall, a rapidly increasing number of Americans are developing and dying from liver cancer, despite the fact that viral hepatitis -- a primary cause of liver cancer -- is preventable and treatable," John Ward, director of CDC’s Division of Viral Hepatitis, stated. "We have the tools we need to reverse this alarming trend -- vaccination for hepatitis B, and testing and treatment for hepatitis B and C. But we urgently need to do more to ensure that these tools are available to and used by everyone who needs them."

Guidelines from the American Association for the Study of Liver Diseases (AASLD) and the Infectious Diseases Society of America (IDSA) recommend that all people living with HCV should be considered for treatment, without waiting until they develop advanced liver disease, as was often done in the interferon era. But treatment is often delayed to the high cost of therapy.

"We believe that appropriate testing and screening for viral hepatitis and increased access to care are the correct strategies for reducing liver cancer incidence and mortality rates," said AASLD president Keith Lindor. "In the past 25 years we have gone from identification to cure of the hepatitis C virus; now the onus is on us to make these life-saving therapies available to all of our patients who will benefit."

3/15/16

Reference

B Ryerson, CR Eheman, SF Altekruse, et al. Annual Report to the Nation on the Status of Cancer, 1975-2012, featuring the increasing incidence of liver cancer. Cancer. March 9, 2016 (online ahead of print).

Other Sources

Centers for Disease Control and Prevention. Annual Report to the Nation: Cancer death rates continue to decline. Press release. March 9, 2016.

CDC. Viral Hepatitis and Liver Cancer. Fact sheet. March 2016.

JM Ward. CDC Statement on Liver Cancer and Hepatitis. March 9, 2016.

JM Ward. Liver Cancer Death Rate Increasing Faster Than All Other Cancers; Implementation of Viral Hepatitis Action Plan Urgently Needed. Blog.AIDS.gov. March 11, 2016.

AASLD. Testing and Access to Care Are Key to Reversing Rising Liver Cancer Incidence and Mortality Rates. Press release. March 9, 2016.

Hepatitis Foundation International. Liver Cancer Related Deaths Increased Faster in the U.S. Attributed to HBV and HCV. Press release. March 9, 2016.