Yesterday & Today
Likely Culprits of a Disease on the Rise
By Jocelyn Selim
The percentage of Americans developing liver cancer has been rising for several decades. The National Cancer Institute estimates that new diagnoses in the mid-2000s were triple those of the mid-1970s. In the period from 2001 to 2006, the most recent period for which statistics are available, the number of new liver cancer diagnoses rose by an average of 3.5 percent a year.
Yet, since 1992, the nation’s blood supply has been screened for both hepatitis B and C—two of the major risk factors for liver cancer. And a vaccine against hepatitis B has been recommended for all children and at-risk adults since 1992, as well. So why are liver cancer rates still rising?
“In the United States, most of this increase can be traced to hepatitis C infections,” says Ghassan Abou-Alfa, a medical oncologist at Memorial Sloan-Kettering Cancer Center in New York City. Although the number of new hepatitis C infections has dropped over the last two decades, approximately 3.2 million Americans are already infected with chronic hepatitis C, according to the Centers for Disease Control and Prevention. “It can take 30 years before chronic infection leads to cirrhosis and hepatocellular carcinoma,” the most common form of liver cancer, says Abou-Alfa. “So many of the cancer cases we’re seeing today are those people who were infected as early as the 1970s.”
Another contributor to U.S. liver cancer incidence, says Abou-Alfa, is nonalcoholic fatty liver disease, a growing problem that is associated with diabetes and morbid obesity—two conditions that are also on the rise.