Cancer disparities by race are widely acknowledged. One in every six black men will be diagnosed with prostate cancer in his lifetime and black men are twice as likely to die from the disease as men of other races.
Why do black men have higher rates of prostate cancer? Could it be that these health disparities, in addition to the recognized social and environmental inequities facing black men, could be explained by genetic differences in prostate tumors? A collaboration of researchers from Boston University School of Medicine (BUSM), UC San Francisco (UCSF), and Northwestern University set out to answer this question. Their findings are reported in Clinical Cancer Research, a journal of the American Association for Cancer Research
The researchers conducted the largest study to date analyzing tumor genetic differences from men of African ancestry. From their investigations, they identified genes that are more frequently altered in prostate tumors from men of African ancestry compared to other racial groups. Why these genes are more frequently altered is still a mystery, say the authors.
Nevertheless, the genetic differences they detected were not significant enough to explain differences in health outcomes. On the upside, this means that as long as black men will still be able to benefit from precision prostate cancer therapies.
"The poorer health outcomes we see in Black men with prostate cancer are not easily explained by any of the distinct gene mutations we identified in prostate tumors from men of African ancestry. This highlights the need to examine the environmental and social inequities that are well known to influence health outcomes across the board," said corresponding author Franklin Huang, MD, PhD. "On the other hand, our tumor genomic analysis also showed that current precision medicine approaches ought to be as effective in Black Americans as they have been for other groups -- if we can ensure that these drugs are applied equitably going forward."
Precision medicine refers to using the genetic changes in an individual’s tumor in order to determine which treatment option will be the most effective for the patient.
"These results reinforce the idea that there can be biological differences in prostate cancers between different ancestral groups and that samples from Black Americans need to be included in future molecular studies to fully understand these differences," said co-corresponding author Joshua Campbell, PhD, who is an assistant professor of medicine at BUSM.
"These types of studies will remain important to understand when certain therapies may preferentially benefit Black patients, who continue to remain underrepresented in clinical trials," Campbell concluded.
Sources: Clinical Cancer Research, Eureka Alert