Differences in education, household income, and health insurance status partly explain reduced prostate cancer survival after surgery in Black males compared with white males, a new study has found.
In the United States, prostate cancer is the second most common cancer in males after skin cancer, according to the American Cancer Society. The society estimate that in 2020, there will be around 191,930 new cases of prostate cancer and 33,330 deaths from the disease.
However, there are large racial disparities in annual cases and deaths. The National Cancer Institute report that there are around 175 new cases per 100,000 Black males, compared with 102 per 100,000 white males.
It also says that annually there are around 38 deaths from the disease per 100,000 Black males, compared with 18 deaths per 100,000 white males.
The lowest mortality from the disease was among Asian American and Pacific Islanders (AAPIs), at around 9 deaths per 100,000.
Scientists believe that genetic differences explain some of the racial disparities in prostate cancer incidence and mortality. But a new analysis of mortality rates following surgery for prostate cancer suggests that socioeconomic inequalities also play an important role.
Researchers at Vanderbilt University School of Medicine in Nashville, TN, have shown that differences in education, household income, and health insurance status account for a large part of the disparity in survival between Black and white males with prostate cancer.
“Socioeconomic status and insurance status are all changeable factors,” says Wanqing Wen, MD, MPH, who led the research. “Unfortunately, the socioeconomic status inequality in the United States has continued to increase over the past decades.”
The findings appear in the journal Cancer.
The scientists analyzed data from the National Cancer Database regarding 526,690 patients with prostate cancer who had their prostate surgically removed between 2004 and 2014.
The analysis included 432,640 white, 63,602 Black, 8,990 AAPI, and 21,458 Hispanic patients. After a median follow-up period of 5.5 years, overall survival rates were high — at 96.2%, 94.9%, 96.8%, and 96.5% for white, Black, AAPI, and Hispanic patients, respectively.
However, in relative terms and after adjusting for patients’ age and the year they received a diagnosis, Black patients had a 51% higher death rate than white patients.
AAPI and Hispanic patients had 22% and 6% lower death rates than white patients.
After adjusting for other clinical and non-clinical factors that might influence survival, the gap in mortality rates between white and Black patients narrowed to 20%.
Differences in education, median household income, and health insurance status made the largest contribution to this disparity. If Black and white patients had equality on all these measures, the actual mortality gap would narrow from 51% to 30%, the researchers estimate.
“We hope our study findings can enhance public awareness that the racial survival difference, particularly between Black and white prostate patients, can be narrowed by erasing the racial inequities in socioeconomic status and health care. Effectively disseminating our findings to the public and policymakers is an important step towards this goal.”
– Dr. Wen
After adjusting for clinical and non-clinical factors, the disparity in survival between AAPI and white patients increased to 35% and remained roughly the same between Hispanic and white patients.
That disparities remain between racial groups even after adjusting for various clinical and non-clinical variables adds to the evidence that genetic differences also contribute to the risk of death from prostate cancer.
One limitation of the research was the relatively small numbers of Black, Hispanic, and AAPI patients in the study cohort, making up less than 18% of the sample. This may limit the accuracy of the figures presented.