Dr. Fitzhugh Mullan, who as a physician, administrator and professor spent a lifetime pushing back against what he saw as inequities in the health care system that left minority groups and low-income people underserved, died on Nov. 29 at his home in Bethesda, Md. He was 77.

Kathy Fackelmann, director of media relations at the Milken Institute School of Public Health at George Washington University, where Dr. Mullan had been a professor since 1996, said the cause was lung cancer.

Dr. Mullan had an earlier encounter with cancer in the mid-1970s, when he was 32. He turned that experience into a book, “Vital Signs: A Young Doctor’s Struggle With Cancer,” and in 1986 he was among the founders of the National Coalition for Cancer Survivorship.

But his main interest was in bringing social justice to the health care system, which he saw as fundamentally flawed both in how it recruits, trains and motivates doctors and in how it delivers care. It was a passion he developed in the summer of 1965, after his first year in medical school, when he spent several months in Durant, Miss., working with impoverished black residents.