ASTRO 2018: Radiation therapy outcomes better for black prostate cancer patients than white patients
Black men with prostate cancer may have “comparatively higher” cure rates when treated with radiation therapy than white men, according to study results presented Oct. 22 at the American Society for Radiation Oncology (ASTRO) Annual Meeting in San Antonio, Texas.
“Our findings suggest that African-American race is not independently associated with worse prostate cancer outcomes,” said lead author Daniel Spratt, MD, of the University of Michigan Rogel Cancer Center in a prepared statement. “When we started this project, we had the commonly-held assumption that African-American men harbor more aggressive disease that leads to lower survival rates. We were surprised, however, that they appear to be more responsive than Caucasian men to radiation therapy and have improved outcomes following this treatment.”
Generally, registries have reported incidences of prostate cancer among black men as 60 percent higher than Caucasian men. Additionally, mortality from aggressive prostate cancer is two to three times higher among black prostate cancer patients.
Spratt and colleagues sought to examine the biological influences that push responses to prostate cancer treatment and could potentially determine the differences in outcomes. They evaluated more than 17,000 men with prostate cancer and looked specifically at the androgen receptor activity, sensitivity to radiation and following outcomes.
The researchers found black men were more likely to have low androgen receptor activity, a “key driver” of prostate cancer. Tumors with low androgen receptor activity were more likely to develop distant metastases within a 10-year period. Additionally, tumors from black men were more likely to have increased sensitivity to radiation, possibly leading to improved outcomes among the demographic.
Spratt et al. also reviewed the outcomes of more than 5,800 patients in four large randomized prostate cancer trials. Their analysis indicated black men who were treated with radiation were less likely to have the cancer return or spread compared to white men. The researchers noted black patients were 18 percent less likely to have biochemical cancer recurrence and 30 percent less likely to have distant metastasis.
“Our results directly question previously held beliefs from population-based registry data that African-American men independently have worse prostate cancer outcomes than Caucasian men,” Spratt said. “These findings strengthen the notion that most of the observed disparity found in population datasets regarding stage-for-stage outcomes between African-American and Caucasian men are reflective of social constructs and not rooted in biology. Not only did both groups generally have similar prognoses, but African-American men treated with radiation therapy actually had higher rates of cure and excellent outcomes. Patients should be treated irrespective of race.”
The ASTRO Annual Meeting is Oct. 21-24 at the Henry B. Gonzalez Convention Center in San Antonio.
As a senior news writer for TriMed, Subrata covers cardiology, clinical innovation and healthcare business. She has a master’s degree in communication management and 12 years of experience in journalism and public relations.