Chicago ? For the first time, doctors say they have found a pill that improves survival in liver cancer, a notoriously hard to treat disease diagnosed in more than half a million people globally each year.

The results in a multinational study of 602 patients with advanced liver cancer are impressive and likely will change the way patients are treated, cancer specialists including the study authors say.

Patients got either two tablets daily of a drug called sorafenib or dummy pills in the study, which started in March 2005. Some patients are still alive, although on average, sorafenib patients survived 10.7 months versus almost 8 months for those on dummy pills. That’s a difference of 44 percent, or about three months.

That type of survival advantage “has never happened” with liver cancer “and is a major breakthrough in the management of the disease,” said Dr. Josep Llovet, the lead author.

“That may not sound like a lot of time,” but for liver cancer, “this is actually a quite impressive gain,” said Dr. Nancy Davidson of Johns Hopkins’ Bloomberg School of Public Health. “It is the first effective systemic treatment for liver cancer, which is such a huge problem internationally.”

Sorafenib attacks cancer with a targeted double-barreled approach. It zeros in on malignant cells themselves and cuts off the blood supply feeding the tumor. It is believed to work on tumors within the liver and those that have spread elsewhere.

In the study, tumors didn’t shrink or disappear but in many cases they also didn’t grow.

“You are not curing the disease but you are delaying the progression of the disease significantly and strikingly,” said Llovet, of Mount Sinai School of Medicine in New York and Hospital Clinic of Barcelona, Spain.

The study was halted early, in February, because of the good results, and patients on dummy pills were switched to sorafenib.

“This is a very good step forward in this disease,” said Dr. Emily Chan of Vanderbilt-Ingram Cancer Center in Nashville, Tenn.

Results were prepared for release Monday in Chicago at the American Society of Clinical Oncology’s annual meeting.

The drug, sold under the brand name Nexavar, is approved in the United States and dozens of other countries to treat advanced kidney cancer. It is marketed by Bayer Pharmaceuticals Corp. and Onyx Pharmaceuticals Inc., which funded the liver cancer study. They hope to receive approval for liver cancer use from U.S. and foreign regulators.

Llovet has done consulting for the sponsors.

Liver cancer is diagnosed in about 19,000 Americans annually but is much more common elsewhere and is the fifth most common cancer globally. Risk factors include chronic liver infections and some forms of hepatitis. The disease is common in China and countries without widespread use of the hepatitis B vaccine, which is routinely given to U.S. infants.

Liver cancer doesn’t respond well to conventional chemotherapy and is often diagnosed too late for surgery to be an option. Many patients die within a year of diagnosis.

Robert Throckmorton, a 73-year-old attorney in Orange County, Calif., said his doctor told him “You better get your affairs in order” after he was diagnosed with inoperable liver cancer last August.

But then the doctor offered sorafenib off-label, and Throckmorton readily agreed. He did not take part in the study.

After nine months on the drug, Throckmorton said his cancer shows no sign of progression and he has no significant side effects. He said he walks three miles six days a week to stay active and feels fine.