Dr. Hahn specializes in lung cancer and sarcoma. He has moved up the ranks at M.D. Anderson since arriving in 2015, when he served as chairman of the radiation oncology department. In 2017, he was named the hospital’s chief operating officer and in 2018, the chief medical executive. Before coming to M.D. Anderson, he was chairman of the radiation oncology department at the University of Pennsylvania’s Perelman School of Medicine from 2005 to 2014. Dr. Hahn was a senior investigator at the National Cancer Institute (NCI) from 1989-1996. Dr. Hahn received his medical degree from Temple University, Philadelphia, PA, in 1984 and his B.A. in Biology from Rice University, Houston, TX, in 1980. He completed his residency in radiation oncology at NCI, his fellowship in medical oncology at NCI, and his residency in internal medicine at the University of California, San Francisco Hospitals. In 2017, Dr. Hahn stepped in to run M.D. Anderson after Dr. DePinho announced his resignation. At the time, the cancer center was operating at a financial loss, and a series of scandals involving Dr. DePinho — including his ties to for-profit companies — had taken a toll on morale, as did the layoffs of about 800 people.By the end of the year, M.D. Anderson had returned to financial stability.