The M.D. degree comes with a label of special knowledge and authority, Dr. Harold Varmus, director of the National Cancer Institute, told Baylor College of Medicine graduates Tuesday night. It also comes with responsibility that extends beyond health care and patients, he said.

"Your views and actions can -- and should -- extend well beyond the immediacy of medical practice…to those difficult places where medical knowledge and social policy intersect, to those places where public policies affect the health of our neighbors and even the future of our species," he said.

Varmus addressed the 191 medical school graduates, 82 graduates from the Graduate School of Biomedical Sciences, faculty, family and friends at the ceremony at Jones Hall in downtown Houston.

Varmus, the co-recipient of the Nobel Prize for Physiology or Medicine in 1989 for his studies on the genetic basis of cancer, challenged the graduates to place importance on social responsibility in their careers. Varmus was named director of the National Cancer Institute in 2010 after serving for 10 years as president of Memorial Sloan-Kettering Cancer Center and six years as director of the National Institutes of Health.

He listed four issues to which physicians can bring a unique public and personal health perspective:

Gun control. The issue of guns in the U.S. society is contentious, he said. "But I'd like to hear more MD's using their authority to describe the effects of guns on public health, not just murders, but also suicides, accidents, and severe injuries."

Science and math education. "If we want to improve the ability of our citizens to adapt to rapid changes in medical science, we need more than the kind of medical training and medical research that is done here at Baylor. We also need a general population taught at earlier stages to understand, appreciate, and evaluate the evidence that will increasingly serve as a basis for healthy living and good medical practice."

The environment. "I don't hear much comment about the implications for health and the future of our species," he said. "Where are the authoritative medical voices noting the health effects of rising ocean levels on people living in lowland habitats? The voices pointing out that warming will produce a resurgence of insect vectors for malaria, dengue, and other infectious diseases? The medics who warn how crowding and hunger and water shortages will predispose our species to violence and other social maladies?"

Rising costs of health care. "If we don't do a better job controlling costs, our entire economy, not just our entitlement programs, will be further jeopardized," he said. Physicians must be part of the solution and the reform efforts.

Dr. Paul Klotman, president and CEO of BCM, presented four honorary degrees at the commencement ceremony.

Doctor of Humanities in Medicine degrees were awarded to Corbin J. Robertson Jr. and Dr. Miguel "Mike" Nevarez. This degree is awarded to individuals who have provided exceptional support or service, either directly or indirectly, to BCM or to academic medicine as a whole.

Robertson, a member of the BCM board of trustees, chair of the Best Minds Best Medicine Campaign and chair of the Board of Trustees from 2001 to 2006, was recognized for his leadership at BCM and for the sustained support of BCM by the Cullen family since the College moved to Houston in 1943.

Nevarez, former president of The University of Texas Pan American, was recognized for his central role in creating the Premedical Honors College with BCM in 1994 and for his tireless efforts to improve educational opportunities for students in the Rio Grande Valley.

Doctor of Letters in Medicine were awarded to Dr. Barry Coller and Varmus. The Doctor of Letter is awarded to physicians who have excelled in medicine through teaching, research or public service and whose acts have brought credit or advancement to BCM or to the profession of academic medicine.

Coller, a highly respected physician-scientist who joined Rockefeller University in 2001 as the first David Rockefeller Professor, head of the Laboratory of Blood and Vascular Biology, physician in chief of the Rockefeller University Hospital and vice president for medical affairs. He also serves as principal investigator of the university's Clinical and Translational Science Award, director of the Rockefeller University Center for Clinical and Translational Science and director of the Center for Basic Translational Research on Disorders of the Digestive System.

Varmus, director of the National Cancer Institute since 2010, is a member of the U.S. National Academy of Sciences and the Institute of Medicine and is involved in several initiatives to promote science and health in developing countries. Varmus was a co-chair of President Obama's Council of Advising on Science and Technology, was a co-founder and chair of the Board of the Public Library of Science and chaired the Scientific Board of the Gates Foundation Grand Challenges in Global Health.

In addition, Distinguished Leadership Awards were presented to Dr. Bobby R. Alford, distinguished service professor at BCM in the Bobby R. Alford Department of Otolaryngology – Head and Neck Surgery, and Dr. Bert O'Malley, professor and chair of molecular and cellular biology at BCM, in recognition of their leadership at BCM for more than 40 years.

Also speaking at the event were Christopher Michael McGraw, representing the Graduate School of Biomedical Sciences, and Faheem Ahmed, president of the graduating medical class.