Recovery of serum testosterone, LH and FSH levels following neoadjuvant hormone cytoreduction and radical radiotherapy in localized prostate cancer.

This study was carried out to evaluate the possible long-term endocrine effect of short-term neoadjuvant leuteinizing hormone-releasing hormone analogue (LHRHa) administration in localized prostate cancer. A total of 419 men were treated for 3-6 months at The Royal Marsden NHS Trust by neoadjuvant androgen suppression using monthly depot injections of LHRHa before radical radiotherapy. Serum testosterone (852 measurements), leuteinizing hormone (LH) (799 measurements), and follicle-stimulating hormone (FSH) levels (801 measurements) were grouped according to their timing in relation to hormonal treatment and then analysed. Suppression of pituitary gonadotrophins and testosterone after the administration of LHRHa and their recovery after cessation of the drug was clearly observed. Median serum testosterone levels decreased from 16 nmol/l to 14 nmol/l when comparing prehormonal and follow-up phases. The same comparison showed an increase in median serum LH and FSH levels, with the median LH rising from 5 u/l to 8 u/l and the median serum FSH rising from 6 u/l to 20 u/l. On long-term follow-up, three of 256 men have remained with testosterone levels in the castrate range. Similar highly significant results were seen in subgroup of 103 men who had both pre-LHRHa and follow-up hormone levels analysed (P=0.012, P<0.001, P<0.001 for testosterone, LH and FSH respectively). Our data suggest the possibility of residual gonadal dysfunction after short-term LHRHa administration and radical radiotherapy in localized prostate cancer. Serum testosterone levels are restored to normal levels in the majority of patients, with a compensatory increase in serum levels of LH.