Is prostate-specific antigen a valid surrogate end point for survival in hormonally treated patients with metastatic prostate cancer?
It is a common misconception that high correlation between biomarkers and true end point justify the use of the former as surrogates. To statistically validate surrogate end points, a high correlation between the treatment effects on the surrogate and true end point needs to be established across groups of patients treated with two alternative interventions. The levels of association observed in this study indicate that the effect of hormonal treatment on OS cannot be predicted with a high degree of precision from observed treatment effects on PSA end points, and thus statistical validity is unproven. In practice, non-null treatment effects on OS can be predicted only from precisely estimated large effects on time to PSA progression (TTPP; hazard ratio,<0.50).
Wisconsin has done well in reducing overall mortality in persons 45-64 years of age over the last 2 decades. Future challenges include reducing health disparities between blacks and whites.