African American men respond better to treatments for advanced prostate cancer in clinical trials

Racial differences have long been evident in prostate cancer statistics. In particular, African American men are diagnosed with prostate cancer more often than white men, and they’re also nearly twice as likely to die of the disease.

But new research also shows that African American men who receive the most advanced treatments for late-stage prostate cancer can live at least as long — or even longer — than their Caucasian counterparts.

Why is this the case? Scientists are searching for an explanation. “The fact that African American men have better survival is of huge research interest,” said Dr. Stephen Freedland, a urologist at Cedars-Sinai Medical Center in Los Angeles. “If we can figure this out, we’ll obtain key insights into the factors driving survival in late-stage prostate cancer. And that in turn will help spur better treatments for all men — regardless of race.”

Each year, about 160 per 100,000 African American men receive a prostate cancer diagnosis. That’s three times higher than the comparable figure for white American men, and it’s also higher than the number of black men diagnosed annually with prostate cancer in Africa. It’s possible that dietary or environmental factors — perhaps in combination with genetic susceptibilities — put African American men at greater risk in the United States. But African American men also tend to have less access to health care than white Americans, and many of them are diagnosed after their tumors have already begun to metastasize, or spread.

A surprising survival advantage

What the new research shows, however, is that survival advantages can favor African Americans who undergo treatment for advanced prostate cancer in clinical trials. One study  pooled data from nine clinical trials, enrolling a combined 88,200 men with metastatic prostate cancer who were treated with a chemotherapy drug called docetaxel. The African American and white men had similar survival rates — 21 months and 21.2 months respectively. But after adjusting for factors such as age and prostate-specific antigen levels, the researchers found that African Americans were 20% less likely to have died during the course of those trials than their white counterparts.

Freedland co-authored another recent study showing that African Americans respond better to newer drugs that target testosterone, which is a hormone that drives prostate cancer to grow faster. Using data gathered by the Veterans Health Administration between 2013 and 2018, the researchers looked at how long African American and white men with metastatic prostate cancer lived after treatment with one of two drugs: abiraterone acetate or enzalutamide. They had access to records from nearly 3,000 men. The unpublished results, presented at a medical conference in February, showed that median survival among the African Americans lasted 30 months, compared to 26 months among their white counterparts. “So, the key takeaway is that if they get to advanced prostate cancer, and are treated equally in an equal access medical center, black men can have similar or even better outcomes,” Freedland said.

The data still need to be confirmed in additional research, Freedland emphasized. But in the meantime, the studies add to a growing body of evidence that’s changing how scientists look at racial differences in prostate cancer. Ideally, the research will reveal new biological insights into prostate cancer, and allow doctors to tailor treatments more effectively.