Do prostate exams really save lives? Are cancer patients in poor cities being treated with the same quality of care as their wealthier counterparts? With cancer the second highest cause of death in the U.S., these questions have consumed 50-year-old Dr. Brawley for most of his extensive medical career.

Dr. Brawley's solid footing among the medical elite is an unlikely one. Growing up in the inner city of Detroit in the 1960s, he saw firsthand the lack of health care his neighbors received, and particularly, the distrust many in his predominantly African-American community had of doctors.

"There were a lot of blacks who were suspicious of people in medicine, concerned," said Dr. Brawley. "There was a lot of concern that people weren't being given the truth." It didn't help that back then, and even today, the proportion of minority doctors in the U.S. is extremely low -- at just 6 percent.

One of his professors at University of Chicago encouraged Dr. Brawley to pursue a subject he had always had an interest in -- science. After medical school, Dr. Brawley went on to practice oncology and hold a host of leadership positions, including teaching hematology, oncology and epidemiology at Emory University and serving as medical director of the Georgia Cancer Center for Excellence at Grady Memorial Hospital in Atlanta, Georgia.

Dr. Brawley continues to lead in the field of cancer research and education in his current position as chief medical officer of the American Cancer Society. But the "bread and butter" that puts Dr. Brawley on this list goes back to those questions that Dr. Brawley discussed in scientific detail during his interview: cancer treatment, prevention and detection, and fair medical treatment for all.

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Dr. Brawley led the National Cancer Institute Prostate Cancer Prevention Trial, and also focuses his research on breast cancer and health disparities. One issue Dr. Brawley takes up is the controversial question of prostate exams. According to Dr. Brawley, the benefits of prostate exams may have been exaggerated, but some others in the medical field disagree.

While Dr. Brawley said he has received his share of controversy for his views on cancer screenings, there are still many in his profession who applaud his achievements. "He's been quite passionate about these issues; some people look at that [controversy about screening] and they decide to not stick their neck out in the public debate, but that's not what Otis is about," said Dr. William Nelson, director of the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University. "He'll take credit for what he said and he doesn't hide from it."

As cancer research continues to reveal new information on testing and finding a cure, being straightforward may be what's necessary to effectively win the battle over this disease.