Multiple Factors Drive Ongoing Rise In Liver Cancer

Multiple Factors Drive Ongoing Rise In Liver Cancer- The U.S. incidence of hepatocellular carcinoma continues to rise, and will likely remain on that trajectory for at least a decade, due to the epidemics of obesity and type 2 diabetes, as well as infections with hepatitis B and C.

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GI & HEPATOLOGY NEWS July 2012 Issue

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Multiple Factors Drive Ongoing Rise In Liver Cancer
BY MITCHEL L. ZOLER

Elsevier Global Medical News SAN DIEGO – The U.S. incidence of hepatocellular carcinoma continues to rise, and will likely remain on that trajectory for at least a decade, due to the epidemics of obesity and type 2 diabetes, as well as infections with hepatitis B and C.

“I think rates will increase for another 10-20 years,” predicted Dr. Alita Mishra, one of two researchers who reported results on this topic at the annual Digestive Disease Week. The two investigators conducted independent studies that revealed increased rates of hepatocellular carcinoma (HCC) in the United States during the 2000s.

Greater vigilance is therefore needed to spot incident cases early, Dr. Mishra said in an interview. While patients with hepatitis C who develop cirrhosis usually undergo routine routine, serial ultrasound screening for liver lesions, regular surveillance occurs less often in patients with cirrhosis related to hepatitis B, or those with cirrhosis due to nonalcoholic fatty liver disease (NAFLD) that is secondary to obesity or type 2 diabetes.

“Patients with cirrhosis should undergo regular HCC screening regardless of the underlying cause,” Dr. Mishra said.

One analysis, based on data collected by the Surveillance, Epidemiology and End Results (SEER) registry of the National Cancer Institute, showed that U.S. HCC rates rose threefold from 1975 to 2007, including a 33% rise during 1998-2007, Jessica A. Davila, Ph.D. reported at the meeting.

The second analysis, using data from the Nationwide Inpatient Sample (NIS), showedthat the number of patients hospitalized with HCC per 100,000 hospital discharges jumped from 148 in 2005 to 213 in 2009, said Dr. Mishra, a hospitalist at Inova Fairfax (Va.) Hospital.

“HCC is rising because of hepatitis C viral infection, especially in people born during 1945-1965,” Dr. Mishra said in an interview. Many of these people don’t know they are infected, and it usually takes decades for them to develop HCC. The second big factor is the rising prevalences of obesity and type 2 diabetes.

“Hepatitis C infections are now falling, so perhaps the rise in new HCC cases will eventually peak, but not if other factors like obesity and type 2 diabetes continue to push it up,” she said.

“What is driving a lot of the increase is hepatitis C virus, and the high prevalence of hepatitis B virus in foreign-born Asians,” said Dr. Davila, a clinical epidemiologist at the Houston VA Medical Center and Baylor College of Medicine in Houston.

“A lot also has to do with obesity and type 2 diabetes and their association with nonalcoholic fatty liver disease, especially in middleaged, Hispanic women. I think we’ll see the greatest increase in HCC in women during the next 2 decades,”

Dr. Davila said. She also predicted increasing numbers of hepatitis C virus–driven HCC cases in the short term. “As the [infected] cohort ages, increasing numbers will develop advanced fibrosis and eventually HCC,” she said. Dr. Davila’s study used data from SEER, which the National Cancer Institute began in 1973 to collect data on cancer cases from about 14% of the U.S. population in selectedstates and metropolitan areas. During 1975-2007, SEER tallied a total of 21,472 HCC cases, about 80% of which occurred in people aged 50-79 years; roughly 75% of cases were in men.

HCC incidence rose from 1.6 cases per 100,000 people during 1975-1977 to 4.8 per 100,000 in 2005-2007. Roughly a tripling of cases during the three decades occurred in both sexes. The greatest increase occurred among people aged 50-59 years, with a nearly fivefold jump, from 2.6 to 12.6 per 100,000 between 1975- 1977 and 2005-2007. The smallest rise was 2.4-fold among people aged 70-79.

By 2005-2007, the highest rate per 100,000 was among Asians, at 10.3, followed by 8.2 in Hispanics, 7.5 in blacks, and 3.7 in whites (see graphic).

Dr. Mishra’s study used data collected in NIS by the Agency for Healthcare Research and Quality from about 1,000 hospitals in 44 states. The number of patients hospitalized with HCC (not confined to incident cases) rose from 9,537 in 2005 to 13,689 in 2009.

During the 5-year period, in-hospital mortality of HCC patients dropped from 120 per 1,000 cases in 2005 to 95 per 1,000 cases in 2009, and the median length of stay fell by about0.5 days.

There was an uptick in the percentage of cases having “major” or “extreme” illness, from 52% in 2005 to 63% in 2009, and the average number of comorbidities also rose steadily during the 5 years studied. Dr. Davila and Dr. Mishra reported having no conflicts of interest. ■

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