The world’s third most deadly cancer is becoming a greater problem here.

Every year, about 700,000 people die of liver cancer. I am referring to cancers that start in the liver, not those that have spread there. Spread to the liver is a very common problem in patients with cancer. But, in my practice, I rarely saw cancers that started in the liver. That may change for newer generations of American oncologists.

Most liver cancer is found in developing countries, particularly in Asia. Half of all cases are diagnosed in China where the rate of liver cancer is about 5 times that in the U.S. Most of the liver cancers in China are caused by infection with hepatitis B virus. But this should become less of a problem in the future. We now have a vaccine to protect against infection with this virus and the number of liver cancers caused by this virus will drop.

In the U.S., we are not seeing a drop in liver cancers even though immunization against hepatitis B is becoming widespread. In fact every year the number of cases increases by around 4 percent. This year, it is expected that 20, 000 Americans will die of this disease. This puts liver cancer in the top ten of killer-cancers.

So why are we seeing an increase in liver cancer? One main reason is infections with the hepatitis C virus. We can immunize against hepatitis B virus, but not hepatitis C virus. That vaccine hasn’t been developed although I am fairly sure lots of drug companies are trying to develop one. Hepatitis C, like hepatitis B virus is transmitted by blood and sex. Now our blood supply is almost completely free of the C virus, but having unprotected sex with a carrier or shooting up with drugs has become the major way this disease is transmitted.

Another common cause is alcoholism. Big time drinkers develop cirrhosis, which can eventually lead to liver cancer if something else doesn’t kill these imbibers. Because they often smoke there is a big chance other cancers will take them away first.

And there is a new kid on the block causing liver cancer, part of the deadliest epidemic to strike us recently – obesity. When I was growing up, NASH stood for an automobile manufacturer, now extinct. Today it stands for Non-Alcoholic SteatoHepatitis. This is also known as fatty liver although the two disorders are slightly different. But now we are seeing these people develop liver cancer at a faster rate than healthier thinner fellow Americans. And as we all know, obesity is a problem that isn’t going away and I suspect that this cancer won’t either.

Unfortunately, liver cancer is usually fatal. Most people with this cancer die. The five-year survival rate is around 15 percent. This low rate has not been helped by periodic screening with ultrasound of the liver and blood tests that can detect the disease at its earliest stages.

It is unfortunate that while the numbers for many cancers are improving, it isn’t happening for liver cancer. This is mostly a self-induced disease. And we have added a new cause, obesity, to the old causes of hepatitis from unprotected sex, intravenous drug use, and alcoholism.