Predictors of lymphatic spread in prostatic adenocarcinoma: uro-oncology research group study.

There were 122 patients with biopsy-proved adenocarcinoma of the prostate and negative radioisotopic bone scan who were subjected to lymphangiography, determination of serum prostatic acid phosphatase, measurement of the size of the lesion, recent pathologic grading of the needle biopsy of the primary tumor and staging pelvic node dissection. The purpose of this study was to determine which of these variables would be most accurate in predicting the presence or absence of positive nodes. Patients with a Gleason scale of less than 5 had only a 13 per cent chance of having positive nodes, whereas patients with a high Gleason scale of 9 or 10 had a 100 per cent chance of having positive nodes. Lymphangiography, size of the prostatic lesion and serum acid phosphatase were not sufficiently accurate to act as predictors of lymphatic extension and precluded the necessity for staging pelvic node dissection.