Prostate cancer grading: the NPCP system.

The use of the NPCP grading system does not contradict the principle that an accurate prediction of tumor volume, presence, and extent of metastases, therapeutic response, and clinical behavior of prostate cancer cannot be entirely based on the grade of the disease at the time of initial diagnosis. The morphology of prostate cancer, like any other cancer, is probably no more than one of a group of parameters that are decisive for the prediction of the biology and clinical course of the disease. Nevertheless, the present data support the premise that the NPCP system of grading prostate cancer, among others, is a very helpful indicator of the extent and behavior of prostate malignancy. Table 6 illustrates the correlation between grades and stages of prostatic carcinoma that can be drawn from the preceding data.