Eleven once-terminal cancer patients are living free of malignancy after undergoing pioneering transplant surgery that replaced four abdominal organs and left most without stomachs, their surgeon said Friday.

"We're pushing ourselves to the limit," transplant pioneer Thomas E. Starzl of the University of Pittsburgh said in an interview.The transplants, believed to be the first of their kind, have been performed on 10 men and three women since June at Presbyterian-University Hospital. Two patients died, one of them after a second transplant, Starzl said.

"It's revolutionary," said Dr. Israel Penn, professor of surgery at the University of Cincinnati who keeps a worldwide transplant tumor registry. "It's a very drastic operation. But with patients of cancers of this type, you have to do very drastic operations to save their lives."

All 13 patients were near death and their tumors were inoperable, Starzl said. The tumors were all located in the pancreas and liver areas. All but the most recent survivors, including one who underwent the surgery Monday, are home.