SEATTLE – April 24, 2017 – A study published today in the journal Cancer, led by Fred Hutchinson Cancer Research Center, offers further evidence that prostate cancer is more prevalent – and can be more aggressive – in black men, and that black men are at increased risk of developing the disease at a younger age compared to the general population.
Using computer models and data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results, or SEER, program, the team of researchers led by Fred Hutch biostatistician Dr. Ruth Etzioni determined that the higher incidence and death rates were related to differences between black men and the general population in how prostate cancer may develop and progress. They estimated that black men had a relatively higher risk — 30 to 43 percent compared to 24 to 29 percent among men in the general population — of developing prostate cancer by age 85.
More specifically, the study showed that, by the time their disease would have been detected without screening, black men with prostate cancer had a risk of 9 to 13 percent that the cancer would have spread beyond the prostate — a risk that is 44 to 75 percent higher than that of the general population. This suggests black men are more likely than others to develop fast-growing prostate cancers.
“That doesn’t mean they all progress faster,” Etzioni said. “But the fraction that progresses faster is higher in this population than in the general population. And the fraction that gets prostate cancer is also higher.”
One thing the researchers couldn’t tell from the models was the root cause or causes of the higher rates – in other words, whether they were due to biological, behavioral or environmental issues.
The new study, which involved investigators from Fred Hutch, the University of Michigan and Erasmus University, comes as experts are re-evaluating the value of the prostate-specific antigen, or PSA, blood test in the general population, which in recent years has become somewhat controversial since the vast majority of cancers it uncovers are very slow-growing.
Etzioni, whose research specifically focuses on the effectiveness of screening for both prostate and breast cancers, believes more guidance may be in order.
“If we know that the cancer is more aggressive in African-American men, it suggests that they should be screened more often,” she said. “And maybe we want to start screening them at a younger age.”
Etzioni and her colleagues said their new findings suggest that black men should have their baseline PSA tested at least three and up to nine years earlier than men in the general population.