THE EFFECT OF RACE/ETHNICITY ON PROSTATE CANCER TREATMENT OUTCOME IS CONDITIONAL: A REVIEW OF WAYNE STATE UNIVERSITY DATA

Abstract

The mortality rate for prostate cancer in black American men (AAMs) is 2 times greater than that in other ethnic groups. However, there is considerable controversy as to whether race/ethnicity is an independent predictor of survival outcome. We present conditions in which race/ethnicity is and is not an independent predictor of survival outcomes. We examined the conditions of age, stage and year of diagnosis, and the role of race/ethnicity on disease-free survival in men who underwent consecutive radical prostatectomy as monotherapy from 1990 to 1999. Data were collected from 229 AAMs and 562 white American men prospectively in the Karmanos Cancer Institute Prostate cancer data bases. When the majority of the cohort had pathologically organ confined disease, race/ethnicity was not an independent predictor of disease-free survival. When the majority of the cohort had a mean age of 70 years or greater, race/ethnicity was not an independent predictor. In studies done in the late 1990s, when the stage of radical prostatectomy cases had shifted toward pathologically organ confined disease as the dominant stage, race/ethnicity was not an independent predictor. However, if the cohort was diagnosed at younger age and/or with more advanced prostate cancer, race/ethnicity became an independent predictor. In the early 1990s there was pathologically advanced disease in the majority of our cohort. Race/ethnicity as an independent predictor of prostate cancer is conditional and dependent on age, stage and year of diagnosis. Year of diagnosis is associated with a stage shift to earlier staged prostate cancer from the early to late 1990s. In general, study cohorts are often subranges of the entire spectrum of prostate cancer that are limited by these factors, especially stage at diagnosis and treatment. If diagnosed and treated early enough, although there is evidence suggesting that AAMs have more aggressive disease biologically, the role of race as a factor in outcome is significantly decreased. The age factor is more complex and must be discussed in more detail.