GnRH receptor and androgen receptor status and outcome of advanced prostate carcinomas.

BACKGROUND

The effect of gonadotropin-releasing hormone (GnRH) analogs on prostate carcinoma is partly a result of breaking the pituitary-gonadal axis, and partly the direct action on tumor cells expressing the GnRH receptor (GnRHR). The aim of this study was to detect the extent of correlation between the expression of GnRHR and also the androgen receptor (AR) and the efficacy of total androgen blockade (TAB).

PATIENTS AND METHODS

Needle biopsy samples of twenty advanced prostate carcinoma patients were investigated histologically regarding Gleason score, AR and GnRHR status of the tumor cells. An affinity purified polyclonal antibody reacting with GnRHR and a monoclonal antibody for AR were applied for immunoperoxidase reactions. TAB was started in each case. Pathological, radiological and laboratory-prostate-specific antigen (PSA) data obtained before the start of TAB and survival, PSA values, and radiological findings after three years of TAB were related to AR and GnRHR.

RESULTS

Regarding the clinical, radiological and laboratory findings before and after three years of TAB, 13 patients (group A) were considered to show a favourable' and 7 (group B) to show a 'poor' outcome. Twelve patients out of 14 with AR-positive tumor cells and all nine patients with GnRHR-positive tumor cells, as well as all eight patients with both AR- and GnRHR-positive tumor cells belonged to group A. The majority of AR-negative, GnRHR-negative or both AR- and GnRHR-negative cases belonged to group B.

CONCLUSION

The presence of GnRHR and AR or both of these receptors indicates a more favourable outcome of advanced prostate carcinoma when treated with TAB, compared to GnRHR- and AR-negative cases. GnRHR and AR negativity may indicate a need for supplementary chemo- or radiotherapy.