[Systematic morphometry of radical prostatectomy samples. A guideline for general practice].

The predictive value of quantitated tumor volume for the prognosis of the individual patient with prostate cancer has been established in analysis of more than 500 radical prostatectomy specimens at Stanford Medical Center. The Stanford technique for detailed tissue sectioning involves considerable time and expense plus computer planimetry. Therefore we have developed two simplified protocols which are suitable to routine diagnostic pathology. Histologic slides of 145 radical prostatectomy specimens, as evaluated by the Stanford technique, were reviewed and a selection of slides was made in a systematic fashion according to two protocols ("bilateral" and "parasagittal"). Tumor volume was estimated manually from this reduced sample of slides by comparing cancer areas to a millimeter grid. The bilateral protocol used an average of 11.7 slides per case (range 8-20), the parasagittal protocol used an average of 8.8 slides per case (range 6-15) versus an average of 26.2 slides per case (range 16-67) by the original Stanford technique. Volume estimates were within +/- 20% of true (computer) volume in 96% and 89% of cases, respectively. A simplified tissue sampling technique can yield accurate cancer volume determinations in radical prostatectomy specimens with reduced time and expense.