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Query: UMLS:C0600139 (Prostate Cancer)
 4,540 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of orchidectomy and thus withdrawal of testicular hormones on the biological and immunological properties of plasma LH was studied. Plasma samples were obtained from five men (mean age 71, range 65-81 years) with advanced carcinoma of the prostate, before orchidectomy and 1, 4, 8 and 16 weeks after surgery. LH bioactivity was estimated by a mouse Leydig cell bioassay and immunoreactivity by radioimmunoassay, using the same human pituitary LH standard 68/40. FSH and testosterone were measured by radioimmunoassay. Similar baseline data were obtained from a group (n = 17) of normal adult men (26, 19-36 years). Baseline bioactive (40 IU/l, median) and immunoreactive (10.8 IU/l) LH levels in the patients were higher (P less than 0.01) than in the controls (15.1 and 5.7 IU/l respectively), but bioactive to immunoreactive (B:I) LH ratios (3.4 +/- 0.2 versus 2.8 +/- 0.7) and testosterone levels (15.3 vs 18.7 nmol/l) were no different, consistent with compensated Leydig cell failure in the elderly men. After orchidectomy there was a greater increase in immunoreactive (46.6 IU/l at 16 weeks) than bioactive (80.3 IU/l) LH levels i.e. a fourfold vs twofold increase from baseline values. Consequently the B:I LH ratio decreased significantly (1.8 +/- 0.4 at 16 weeks) from the baseline ratio (P less than 0.0001) and that of the controls (P less than 0.01). These data indicate that acute withdrawal of testicular sex steroids results not only in quantitative change in LH secretion but also in qualitative change that decreases the biopotency of the LH molecules.
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PMID:Changes in the qualitative and quantitative secretion of luteinizing hormone (LH) following orchidectomy in man. 315 Mar 21

The serum concentration of testosterone, luteinising hormone (LH), follicle stimulating hormone (FSH) and prolactin were determined at different intervals after withdrawal of oestrogen treatment in patients with prostatic carcinoma. Oestrogen therapy had been stopped in all patients because of the side effects of oestrogens. There was a negative correlation (r = -0.64) between serum testosterone concentrations and the duration of oestrogen treatment in patients investigated for more than 6 months after withdrawal of hormones. However, the decrease in testosterone concentration seems to be time-dependent. Thus patients who were treated for less than 3 years had normal testosterone concentrations approximately 6 months after withdrawal of the oestrogen therapy. This group of patients had a positive correlation (r = 0.49) between serum testosterone concentration and time elapsed after cessation of therapy. In contrast, patients treated for more than 3 years retained low testosterone concentrations even after 6 months. The other hormones did not vary between the groups. It is concluded that patients with carcinoma of the prostate treated with oestrogens for more than 3 years have an impaired Leydig cell function which might be irreversible.
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PMID:Testicular endocrine function after withdrawal of oestrogen treatment in patients with carcinoma of the prostate. 640 48

Twenty-two patients with advanced prostatic carcinoma were subjected either to orchiectomy (group I, n = 5) or to chronic administration of a gonadotropin releasing hormone agonistic analogue D, Ser (TBU)6, des Gly-NH2(10) LHRH nonapeptide (HOE 766) (group 2, n = 17). Plasma testosterone was similar in both groups prior to treatment (group 1: 636 +/- 129.29, group 2: 580.85 +/- 37.57; X +/- SE). The levels attained in group I were significantly lower (P less than .05) than those of group 2 through eight weeks of follow-up but were similar by the third month. Prostatic size (cm2) as estimated by transabdominal ultrasonography did not differ between the two groups prior to treatment (group 1: 23.6 +/- 3.35, group 2: 21.4 +/- 1.97; X +/- SE). Both therapies resulted in a decrease of prostatic size that was significantly more pronounced (P less than .05) in group I compared with group 2 by the first and third month; by the six month, there was no statistical difference in the prostatic size attained with either therapeutic modality. Persistent suppression of prostatic size was documented in all patients of group 2 chronically (up to 24 months) treated with HOE 766 even when there was evidence of uninhibited or progressive bony metastases. The above data 1) indicate the efficacy of the HOE 766 in inducing medical castration and prostatic shrinkage in advanced carcinoma of the prostate, 2) document the usefulness of transabdominal ultrasound in the follow-up of such patients, and 3) suggest a relationship between the rapidity of tumor shrinkage and Leydig cell suppression.
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PMID:Transabdominal ultrasonography in the evaluation of patients with advanced prostatic carcinoma: effects of castration and of chronic administration of a gonadotropin releasing hormone agonistic analogue. 641 31

Testosterone depletion is the keystone for therapy of patients metastic prostatic carcinoma. Our objective was to investigate Leydig cell function and testosterone levels after withdrawal of long-term endocrine treatment in patients with prostatic carcinoma. Thirteen patients with prostatic carcinoma, previously treated with oestrogens for at least 4 y, were stimulated with 5000 IU human chorionic gonadotrophin (hCG). The stimulation was performed 3-6 y after cessation of the oestrogen therapy. Serum concentrations of testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured before and 24 and 48 h after hCG stimulation. Before hCG stimulation all patients had low serum testosterone concentrations (mean 2.0+/-0.2 nmol/l) and 24 and 48 h after hCG stimulation the values had not significantly increased (mean 2.4+/-0.2 and 2.5+/-1.1 nmol/l, respectively). LH and FSH were within or above the normal range before but after hCG stimulation the values significantly increased. In conclusion, the study shows that the Leydig cells were unable to respond to hCG stimulation more than 3 y after cessation of oestrogen therapy. The Leydig cell function seems to be irreversibly impaired by long-term oestrogen treatment.
Prostate Cancer Prostatic Dis 1999 Jul
PMID:Effects of hCG stimulation after withdrawal of long-term oestrogen treatment in patients with prostate carcinoma. 1249 80