Racial differences in survival among men with prostate cancer and comorbidity at time of diagnosis

Objectives. This study evaluated the effect of comorbidity at diagnosis on racial differences in survival among men with prostate cancer. Methods. Clinical and demographic data were abstracted from records of 864 patients diagnosed at 4 Chicago area hospitals between 1986 and 1990. Comorbidity was scored on the basis of clinical information in the Charlson index. Cause-specific relative mortality adjusted for age, stage, differentiation, and treatment was compared across Charlson scores with Cox proportional hazards functions. Results. Blacks had significantly greater mortality from prostate cancer and other causes (vs Whites, relative risk [95% confidence interval] = 1.84 [1.22, 2.79] and 1.69 [1.33, 2.291, respectively; P<.001). However, differences disappeared as initial comorbidity increased (1.75 [1.33, 2.31] vs 0.90 [0.59, 1.29] for scores =0 and greater than or equal to5, respectively). Conclusions. Absence of a significant preexisting medical diagnosis is associated with a higher risk for excess mortality among Black men diagnosed with prostate cancer.