ST. LOUIS — In 1966, the Rev. Dr. Martin Luther King Jr. said, “Of all the forms of inequality, injustice in health care is the most shocking and inhuman.” While major advances have been made in health care, ethnic and racial disparities remain in the prevention, diagnosis and treatment of many illnesses, particularly prostate cancer.

The risks facing African-Americans are shocking: They have the highest incidence of prostate cancer and the highest mortality rate from the disease of any ethnic or racial group in the United States. One in six African-American men will develop prostate cancer in his lifetime, and one in 23 will die from it. The mortality rate is 2.4 times higher than that of the overall population. Indeed, the racial disparity related to prostate cancer is greater than for almost all other solid tumors.

Beginning in the 1990s, doctors began administering the prostate-specific antigen test, the most significant advancement in the diagnosis of prostate cancer. PSA is a protein secreted by prostate tissue and is easily measured with a simple blood test, allowing for early detection of prostate cancer.

Before the widespread use of PSA screening, advanced or metastatic prostate cancers constituted 25 percent of newly diagnosed cases in white men, and 50 percent in African-American men. These advanced-stage cancers remain difficult to treat and incurable. The most effective therapy includes lifelong testosterone-lowering drugs or castration, with all its grave side effects. Thankfully, with the widespread use of PSA screening, fewer than 5 percent of men with newly diagnosed cases are found to have metastatic prostate cancer.