Evidence for altered hypothalamic-hypophyseal-gonadal axis in untreated patients with testicular germ-cell tumor

To investigate the function of the hypothalamic-hypophyseal-gonadal axis in testicular germ cell tumors, we evaluated gonadotropin responses to gonadotropin-releasing hormone (GnRH) in 12 untreated patients with testicular cancer (5 seminomas and 7 non-seminomas). GnRH was given i.v. at a dose of 100 micrograms as a bolus, and venous blood samples were collected at 0, 20, 60, and 120 min. As controls, 14 healthy males were studied. Basal levels of testosterone, estradiol and prolactin were also detected in each patient. Hormonal serum concentrations were measured by the radioimmunoassay. Mean basal testosterone, estradiol and prolactin levels were not significantly different from those of controls. Patients had a lower FSH and LH peak after GnRH than controls, without, however, any significant difference. As regards histology, non-seminoma patients lacked an FSH response to GnRH and had statistically lower mean peak levels than controls. Moreover, non-seminoma patients had statistically lower mean peak values of LH after GnRH than controls. These data show that patients with testicular germ cell tumor, and more particularly those with non-seminomas, have an altered function of the hypothalamic-hypophyseal-gonadal axis, which is already present prior to therapy. Further studies, particularly in stage I patients treated only with orchiectomy, should be performed to confirm and better define the physiopathologic significance of the altered hypothalamic-hypophyseal-gonadal axis in testicular cancer and to clarify the alteration of fertility, which is frequently present before treatment.