Dr. Donald Gleason, of Edina, a retired professor of the University of Minnesota School of Medicine, led research at the VA Medical Center in Minneapolis and devised the grading system that doctors around the world use today to determine the proper treatment of prostate cancer.

Gleason, whose system and research underpins continuous research into prostate cancer, died of natural causes Dec. 28 in Edina.

The longtime Richfield resident was 88.

"Worldwide, his system is used annually at least 1 million times -- that's the number of people diagnosed with this cancer. In the United States alone, about 230,000 are diagnosed with prostate cancer annually," said Akhouri Sinha, a research scientist who worked with Gleason for 40 years.

Gleason "boiled down the complexities of prostate cancer" to devise his grading system, Sinha said.

"His work was comprehensive, yet simple so that the grading system can be used by pathologists, clinicians and scientists throughout the world," said Sinha, a medical school professor who works at the VA Medical Center.

"His achievement remains unparalleled thus far," Sinha said.

Dr. Bill Swaim, of Burnsville, a retired pathologist and internist, and a former resident of Gleason's, said he was an uncommonly good teacher.

"He was a wonderful mentor. He didn't give you the answer. We would sit and chat, and you discovered the answer with his help," Swaim said.

Gleason grew up in Litchfield, Minn., and completed his undergraduate work at the U of M, where he earned his medical degree in 1944 and later earned a Ph.D. in physiology.

In the mid-1940s, he served as an Army doctor, and in the 1950s, he became chief of pathology at the VA Medical Center, where he worked until his retirement in 1986.

Among honors he received was the American Urological Association's Presidential Citation Award and an Outstanding Achievement Award from the University of Minnesota, both in 2001.

"He was an outstanding pathologist" said Dr. Ellis Benson, of Minneapolis, a retired pathologist at the university, and medical school classmate of Gleason's. "He had a real eye and was able to make true diagnoses."

In 1989, Benson's prostate cancer was diagnosed, and he took the laboratory slides to his friend's house. Gleason pulled out a microscope and graded Benson's cancer.

During treatment at Mayo Clinic, Benson's doctor knew the name on the test immediately, saying "This tumor was graded by Gleason himself," reported Benson.

He is survived by his wife of 62 years, Nancy, of Edina; daughters Donna O'Neill, of Annandale, Va., Sue Anderson, of Burnsville, and Ginger Venable, of Eden Prairie; sister, Barbara Jarl, of St. Paul, and nine grandchildren.

Services will be held at 10:30 a.m. Saturday at the Cremation Society of Minnesota, 7110 France Av. S., Edina.