NEO ADJUVANT GNRH THERAPY AND RADICAL PROSTATECTOMY - EFFECTS ON TUMOROUS AND BENIGN TISSUE VOLUMES - A MORPHOMETRIC STUDY

The effect on tumour and prostate volumes of a 3-month course of neo-a djuvant hormone therapy was studied using computerised planimetry on s erially sectioned specimens obtained by radical prostatectomy. Fifty-f our specimens from patients not receiving pre-treatment were compared to 38 specimens from patients given the gonadotropin-releasing hormone (GnRH) analogue triptorelin for 3 months before the operation. Glandu lar volume and volume of the index tumour was determined. To determine the position of the index tumour within the gland, the centre of mass of the tumour was identified and the distance to the gland margin cal culated. This value (M(1)) represents the sum of the tumour radius and the various amounts of normal tissue. The amount of surrounding tissu e could be approximated by correlating M(1) to the corresponding tumou r volume. Results: The two groups differed significantly in total glan d volumes, but not in tumour volumes. M(1) was strongly correlated to the tumour volume in the treatment group (r = 0.73), whereas in the co ntrol group the correlation was found to be significantly weaker (r = 0.44), indicating that there was less tissue surrounding the tumour in the pre-treated group. In a multiple regression analysis of all 92 pa tients, index tumour volume was found to be associated with total glan d volume, DNA ploidy pattern, tumour grade but not whether or not pre- treatment was given. This study found that the volumes of the single l argest tumour focus were not significantly affected by hormonal pretre atment, and that ''the prostate condenses around the tumour rather tha n that the tumour shrinks back into the prostate''. However, the preci se relationship between tumour epithelial volume and stroma with or wi thout neo-adjuvant hormonal pre-treatment remains to be clarified.