New research has found that adding another chemotherapy (search) drug to standard treatment slightly prolongs the lives of patients with inoperable pancreatic cancer (search), raising the possibility that the combination might cure a greater proportion of people whose tumors are cut out.

Pancreatic cancer has one of the worst prognoses of all types of cancer. Less than 4 percent of patients are still alive five years after diagnosis and most die within a year. Even in the minority of cases where the tumor can be operated on, only about 23 percent remain cancer free.

A study presented Wednesday at the European Cancer Conference found that adding the drug Xeloda, or capecitabine, to standard chemotherapy gave patients whose cancer was inoperable an average of another six weeks of life, increasing survival from six months.

"This is a small improvement, but that's what we do in cancer therapy. We take one step at a time," said Dr. Margaret Tempero, chief of medical oncology at the University of California at San Francisco, who was not involved with the research. "We're starting with a disease that has such a poor outcome that a little change actually is a relatively big difference."

"And it's not so much that this patient group benefited, but that this combination is clearly better, suggesting that one could use this combination following surgery to cure more people," she said. "These patients do get some incremental benefit and it's important for them, but the big home run is curing more people with adaptation of that treatment following surgery."

The study, led by scientists at the Royal Marsden Hospital in London, involved 533 patients whose pancreas tumors could not be operated on because they had spread. Between 80 percent and 90 percent of the 250,000 cases diagnosed globally every year fit this category.

In the study, half the patients were given standard chemotherapy, the drug Gemzar, or gemcitabine. The others got a combination of Gemzar and Xeloda, a chemotherapy used in breast, colon and stomach cancer but never before tried in pancreatic cancer.

In the Gemzar group, 19 percent of patients were alive one year after diagnosis, but in the combination group, 26 percent were still alive.

The average survival was six months in the standard treatment group, compared with 7.4 months in the combination therapy group. Toxic side effects were about the same in both groups.

In the 29 percent of patients whose tumor had only spread to adjacent sites in the body, about half the patients were alive after one year, said Dr. John Neoptolemos of Royal Liverpool University Hospital, one of the study's investigators.

"That actually is really good, because 10 years ago, you'd expect everybody to be dead within the year," he said.

Xeloda is made by Swiss pharmaceutical company Roche. The study was paid for by Cancer Research UK, a London-based cancer research charity.