Prognostic factors in prostate cancer must be significant, independent and
clinically important. "Significant" means the factor rarely occurs by chanc
e, "independent" means the factor retains its value even when new factors a
re added and "clinically important" means the factor influences therapy. Th
ey should furthermore be classified into patient-related, tumor-related and
treatment-related factors. If new prognostic factors are established witho
ut adherence to these guidelines, there results an exponential increase of
meaningless parameters, as an individual patient can only belong to one pro
gnostic group. Prognostic factors with established values are metastases, l
ymph node involvement, grade, positive margins, extracapsular extension and
seminal vesical invasion. Among the classic and new biomarkers, only PSA h
as been of value for prediction of progression-free survival.