In 1947, the Laboratory of Experimental Oncology (LEO) was founded as a collaborative effort between the city of San Francisco, The National Cancer Institute and the UC School of Medicine. The LEO was created with the full support of Surgeon General Thomas Parran, and was an outlying entension of the NCI. LEO was designed for clinical research and filled this need until a large national clinical center opened in Bethesda in 1953.

During its five years of operation (1947-1953), LEO investigators produced 124 scientific papers, based upon 605 “experimental treatments” conducted on 467 cancer patients admitted to the lab’s experimental ward. By the time the lab closed in 1953, 90% of these patients had died, and 82% were autopsied as part of the laboratory’s program.