Effects of long term GnRH analogue treatment on hormone levels and spermatogenesis in patients with carcinoma of the prostate.

The effects of long term GnRH treatment with the biodegradable depot formulation of ICI 118.630 on hormone levels and spermatogenesis were investigated in 18 males with advanced prostate cancer. Plasma levels of FSH, LH, testosterone, DHEA-S and SHBG were monitored at regular intervals. The drug suppressed FSH, LH and testosterone significantly and did not affect DHEA-S and SHBG plasma levels. Tissue specimens for histologic assessment and quantitative analysis of germinal cell types were obtained at secondary orchidectomy in 16 patients immediately following GnRH analogue treatment. Germinal cell maturation was arrested at the spermatogonial stage. In two patients discontinuing treatment histologic assessment of secondary orchidectomy specimens 9 and 10 months after the last GnRH analogue depot injection resulted in germinal cell maturation to late spermatids in part of the tubule cross sections. These results indicate that long term administration of the GnRH analogue fails to produce complete testicular sclerosis and spermatogenic arrest might be reversible.