NEW HAVEN, CT—Every physician knows each patient is different. Prognostic models, however, tend to assume everyone’s the same. That can skew decisions in cancer care.
Researchers at Yale University in New Haven, CT, and the Los Alamos National Laboratory in Los Alamos, NM, investigated how tools used to predict prostate cancer death performed by race or ethnicity. The results of their study were published in conjunction with the 2020 American Society of Clinical Oncologists Annual Meeting held May 29-31.1
The team reviewed records of 98,994 men with prostate cancer confirmed by biopsy between 2002 and 2016 who were treated through the VA Healthcare System. Patients with lymph node or distant metastatic disease at diagnosis were excluded. For the purposes of comparison by race/ethnicity, the researchers excluded patients who were not categorized as non-Hispanic white, non-Hispanic black, or Hispanic.
To validate their results in the future, the researchers also reserved 20% of the cases.
Patients included in this study were 64% non-Hispanic white, 30% non-Hispanic black, and 6% Hispanic.
Differences between the populations appeared from time of diagnosis forward. Non-Hispanic blacks were the youngest patients at diagnosis, with a median age of 63. Both non-Hispanic whites and Hispanic patients had a median age of 66 years at diagnosis.
During the course of follow up, 3,484 veterans died from prostate cancer, representing 15% of the total study population. A total of 23,316 veterans died from all causes.
For patients who were less than 65 years of age at diagnosis, an elevated Gleason score was associated with much higher risk of death from prostate cancer in non-Hispanic white men and Hispanic veterans than in non-Hispanic black men. The difference more than doubled at a Gleason score of 9 and more than tripled at Gleason score of 10. (See chart.)
Conversely, the risk of death from prostate cancer associated with prostate specific antigen (PSA) test scores above 5 for men younger than age 65 at time of diagnosis was much higher for non-Hispanic black veterans than for non-Hispanic whites and Hispanic veterans up to a score of 50. For the highest levels of PSA (50 to 100), Hispanic men had a sudden increase in risk of death that put them nearly on par with non-Hispanic blacks.
Among men over the age of 65 at diagnosis, Gleason score was associated with about equal risk of death in non-Hispanic white and non-Hispanic black veterans and notably lower risk of death in Hispanic veterans. Risk of death from prostate cancer based on PSA score was about the same for all three groups.
Based on these findings, the researchers concluded that “risk associated with Gleason score and PSA varied by age and race/ethnicity.” Further, they recommended that “prognostic models for prostate cancer disease progression must be evaluated in diverse populations and across age strata.”
- Janet T, Danciu I, Justice A, Leapman M, et. al. Predicting prostate cancer death among 98,994 veterans: Differences by race/ethnicity. Abstract e17609. 2020 ASCO Annual Meeting. May 29-31, 2020.