Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to assess the biological significance of low serum androgens comparable to those which remain after castration in men treated for prostate cancer. Silastic depots continuously releasing predetermined doses of testosterone (T) have been implanted into castrated adult male rats in the absence or presence of simultaneous treatment with the pure antiandrogen Flutamide. Quite remarkably, a 3- to 5-fold increase in prostate weight (P less than or equal to 0.001) was observed at plasma T concentrations comparable to those found in the serum of castrated men. Although of lower magnitude, castration levels of plasma T also caused a significant stimulation of seminal vesicle weight (P less than 0.01). This dramatic stimulatory influence of "castration" levels of plasma T on ventral prostate and seminal vesicle weight can be explained by the 13- to 15-fold higher intraprostatic level of the active androgen dihydrotestosterone (DHT) compared to the plasma T concentration. In fact, a near-maximal intraprostatic concentration of DHT is reached at concentrations of plasma T of 0.2-0.5 ng/ml and a positive correlation was found between prostatic DHT concentration and ventral prostate weight. Prostatic growth and DHT concentrations were also positively correlated with ornithine decarboxylase (ODC) activity, an enzyme highly sensitive to androgens in the rat ventral prostate. In fact, a dramatic (30-fold) increase in ODC activity was observed at plasma T values corresponding to those found in castrated men. The level of prostatic beta 2-adrenergic receptors fell within 10 days of castration and an increase in beta 2-adrenergic receptor concentration was observed with low doses of T, thus indicating that beta 2-adrenoreceptor levels are also a sensitive parameter of androgenic activity in the rat prostate.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Castration levels of plasma testosterone have potent stimulatory effects on androgen-sensitive parameters in the rat prostate. 284 94

The effect of flutamide on basal and ACTH-stimulated plasma levels of adrenal androgens was investigated in 6 patients with untreated advanced prostate cancer, aged 52-75 yr. Flutamide was administered (250 mg three times daily) for 10 days; before and after treatment, a synthetic ACTH1-24 stimulation test (250 micrograms im, with blood sampling immediately before and 60 min after the stimulus) was performed. Basal plasma 17OH-pregnenolone (delta 5-17OHP), 170H-progesterone (delta 4-17OHP), androstenedione (A), dehydroepiandrosterone (DHEA) and its sulphate (DHEAS) were unchanged by flutamide treatment. In contrast, basal plasma testosterone (T) concentrations significantly increased (p less than 0.05). The response of cortisol delta 4-17OHP, delta 5-17OHP, A and DHEA to ACTH, as well as the ACTH-stimulated delta 5-17OHP/delta 4-17OHP, delta 5-17OHP/DHEA, delta 4-17OHP/A and DHEA/A ratios, were unchanged by flutamide treatment. These findings indicate that: a) Short-term flutamide administration enhances testicular steroidogenesis, via augmented LH pulse frequency; b) Adrenal steroidogenesis seems to be not affected by the drug, since ACTH-stimulated plasma levels of adrenal androgens and precursors/products ratios were unchanged.
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PMID:The effect of flutamide on basal and ACTH-stimulated plasma levels of adrenal androgens in patients with advanced prostate cancer. 285 89

Patients (154) with clinical stage D2 prostate cancer with no previous endocrine therapy or chemotherapy received the combination therapy with the pure antiandrogen Flutamide and the LHRH agonist [D-Trp6]LHRH ethylamide for an average of 22 months (3-49 months). The objective response to the treatment was assessed according to the criteria of the US NPCP. There was a 6.3-fold increase (29.2 vs 4.6%) in the percentage of patients who achieved a complete response as compared to the results achieved in five recent studies limited to removal (orchiectomy) or blockade (DES or Leuprolide) of testicular androgens. Only 4.5% of patients did not respond to the combination therapy as compared to an average of 18% by standard therapy. The duration of response is also significantly increased in the patients who received the combination therapy. The death rate was decreased by approximately 2-fold between 2 and 3 yr of treatment. The marked (6.3-fold) improvement in the rate of complete objective responses coupled with the 4-fold decrease in the number of non-responders, the increased duration of the positive responses and the 2-fold decrease in the death rate at 2-3 yr of treatment are obtained with the combination therapy using Flutamide and castration with no or minimal secondary effects.
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PMID:Combination therapy with flutamide and castration (orchiectomy or LHRH agonist): the minimal endocrine therapy in both untreated and previously treated patients. 296 37

In order to evaluate the proposed benefit of complete androgen blockade in the treatment of patients with advanced prostatic cancer, we initiated a multicenter prospective and randomized study. At the time of this report 99 patients with newly diagnosed, previously untreated prostatic cancer were randomly distributed to one of the following treatments: group I, orchiectomy plus antiandrogen Flutamide; group II, depot LH-RH analog Zoladex plus Flutamide; group III, orchiectomy alone, and group IV, Zoladex alone. Our preliminary data fail to demonstrate a superiority of total androgen blockade over partial androgen blockade in the treatment of patients with advanced cancer of the prostate.
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PMID:Evaluation of total versus partial androgen blockade in the treatment of advanced prostatic cancer. 297 69

In order to achieve a more complete blockade of androgens of both testicular and adrenal origin at the start of treatment, we have administered the pure antiandrogen Flutamide in association with orchiectomy (13 patients) or the LHRH agonist [D-Trp6]LHRH ethylamide (118 patients) to previously untreated patients with clinical stage D2 prostate cancer. The mean duration of treatment was 491 days (102-1208 days). The response was assessed according to the criteria of the U.S. National Prostatic Cancer Project. A complete response has been observed in 30 patients (23%) while partial and stable responses have been achieved in 50 (38%0 and 45 (34%) patients, respectively. A positive objective response has thus been observed in 125 of 131 patients (95%). Serum PAP became normal before 6 months in all except 8 (6.1%) of patients. Quite remarkably, 23 of 48 patients treated for 2 years (47.9%) have achieved a complete response. Of the 20 deaths, 12 (9%) were due to prostate cancer, while 8 (6%) resulted from other causes. The probability of continuing a positive response after 2 years of treatment (according to Kaplan and Meier) is 60% while the probability of survival at the same time interval is 89%. This survival should be compared to values of approx 50% achieved with previous treatments limited to inhibition of testicular androgen secretion or action. The present data demonstrate that the combined blockade of androgens achieved with Flutamide and castration provides an objective response in approx 95% of patients, and markedly prolongs the period of remission while the death rate within the first 2 years is lower than that obtained with previous treatments. The important prolongation of survival is achieved with an excellent quality of life. Two-hundred and three patients have clinical stage D2 prostate cancer previously treated by orchiectomy, estrogens or LHRH agonists alone received, at the time of relapse, the same combination therapy. Patients already castrated received only Flutamide while, for those previously treated with DES, the estrogen was replaced by the LHRH agonist [D-Trp6]LHRH ethylamide in association with Flutamide. Flutamide was given as additional medication to those already receiving an LHRH agonist alone. Complete, partial and stable objective responses assessed according to the criteria of the U.S. National Prostatic Cancer Project were obtained in 11 (5.4%), 17 (8.4%) and 38 (18.7%) patients, respectively, for a total objective response rate of 32.5%. Progression continued in 137 (67.5%) patients.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Advantages of the combination therapy in previously untreated and treated patients with advanced prostate cancer. 310 Aug 71

In order to clarify the effects of androgen blockade on the hypothalamic-pituitary-testicular axis in man, four patients with advanced prostate cancer, not previously treated, were given oral flutamide, 250 mg three times daily for 9 days. Before, and 7, 8 and 9 days after starting flutamide treatment, on separate days, the following tests were performed: a gonadotrophin pulsatility study, with 20 min interval blood sampling for 12 h, a naloxone test and a GnRH test. Flutamide induced a significant increase in both LH and FSH pulse frequency, while pulse amplitudes and plasma integrated concentrations (IC) of LH and FSH were unaffected. Plasma integrated concentrations of testosterone and oestradiol rose significantly, while that of prolactin was unaffected. The increase in plasma LH concentration induced by naloxone injection was abolished by flutamide treatment. On the other hand, the small FSH response to naloxone was unaffected by flutamide treatment. Response to GnRH was unaffected by flutamide. These results suggest that flutamide exerts effective androgen blockade at the hypothalamic level, since, despite increased plasma testosterone concentrations, gonadotrophin pulse frequency increased and the LH response to naloxone was abolished.
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PMID:The effect of androgen blockade on pulsatile gonadotrophin release and LH response to naloxone. 312 93

The effect of short term administration of flutamide on the hypothalamic-pituitary-gonadal axis was studied in six patients with advanced prostate cancer (C2 stage). Flutamide significantly increased LH pulse frequency in all patients (p less than 0.05 by Wilcoxon's test). The FSH pulse analysis disclosed a similar pattern of LH. Plasma IC-T clearly increased following flutamide therapy; mean IC-T values were 2.67 +/- 0.47 ng./ml. and 4.67 +/- 0.62 ng./ml. before and after flutamide administration, respectively (p less than 0.05 by paired Student's t test). Our study demonstrates that flutamide acts in humans as a selective and specific antiandrogen compound.
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PMID:Short term effects of flutamide administration on hypothalamic-pituitary-testicular axis in man. 312 48

The therapy for the treatment of prostate cancer and other sex-steroid-dependent tumors based on agonists of LH-RH has been made more practical and efficacious by the development of a long-acting formulation of microcapsules of D-Trp-6-LH-RH for controlled release. Antiandrogens, which neutralize the effect of endogenous androgens, have been used also in the management of prostate cancer in man. The effects of a simultaneous administration of the antiandrogen flutamide and microcapsules of the agonist D-Trp-6-LH-RH were studied in the Dunning R-3327H rat prostate adenocarcinoma model to determine whether the combination of these two drugs might inhibit tumor growth more effectively than single agents. Microcapsules of D-Trp-6-LH-RH, calculated to release a controlled dose of 25 micrograms/day for a period of 30 days were injected intramuscularly once a month. Flutamide was administered SC at a daily dose of 25 mg/kg. The therapy was started 100 days after the tumor transplantation and continued for 60 days. Tumor weights and volumes were significantly reduced in rats treated with microcapsules or flutamide alone, but the former drug inhibited tumor growth more than the latter. The combined treatment of flutamide and microcapsules significantly decreased tumor weight and volume, but did not exert a synergistic effect on tumor growth, the reduction being smaller for the combination than for the microcapsules alone. There was a significant elevation of serum testosterone, LH, and prolactin in rats treated with flutamide. On the other hand, in rats given microcapsules of D-Trp-6-LH-RH, testosterone fell to castration levels within 7 days and remained at nondetectable values, serum LH and prolactin levels being also suppressed in this group. The combined administration of microcapsules and flutamide also significantly decreased serum testosterone to nondetectable levels by day 7 and suppressed serum LH and prolactin. Our findings raise doubts of whether the daily administration of the combination of LH-RH agonist with an antiandrogen offers an advantage over the use of microcapsules of an agonist like D-Trp-6-LH-RH alone in the treatment of prostatic carcinoma.
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PMID:Investigation of the combination of the agonist D-Trp-6-LH-RH and the antiandrogen flutamide in the treatment of Dunning R-3327H prostate cancer model. 315 27

One hundred and eighty-six previously untreated patients with clinical stage D2 prostate cancer have been followed according to the criteria of objective response of the National Prostatic Cancer Project (NPCP). All patients received combination therapy with the antiandrogen Flutamide and the LHRH agonist (D-Trp6, des-Gly-NH2(10)]LHRH ethylamide (or surgical castration, 10 patients) as first treatment. Forty-nine patients (26.3%) achieved a complete response as best response while 56 (30.1%) and 69 (37.1%) patients had partial and stable responses, respectively, and only 12 patients (6.5%) did not respond to treatment. The median times required to achieve stable, partial and complete responses were 155, 183 and 401 days, respectively. The best response achieved has a major influence on the probability of continuing response and survival. While the 50% probability of continuing response is more than 3 years for the complete responders, it is reduced to 630 and 517 days for partial and stable responders, respectively. While the non-responders have a median life expectancy of 10.0 months, this value is increased to 30.3 and 37.8 months for the stable and partial responders, respectively. The best probability of survival is for the complete responders with a 95.9% probability of survival at 3 years. There is no significant correlation between the time required to achieve a best response (phase 1) and the duration of the response before progression occurs (phase 2) or the time between progression and death (phase 3) for any of the categories of responses. A longer period of time required to achieve a complete response is associated with a longer survival. When analysis is made, in an attempt to predict response, of the baseline characteristics of the patients before treatment, a low number of bone metastases and better performance status are associated with a greater chance of achieving a complete response while partial, stable and progression responses cannot be predicted from the baseline characteristics. The present data show the importance of standardization of the objective criteria of response to treatment in advanced prostate cancer. Thus, the patients who achieve a complete response have a much more favorable prognosis while partial and stable categories of response have a closely similar prognosis which is inferior to the complete responders. Moreover, the present data indicate that the stable category of response has an important prognostic value which is almost superimposable and not statistically different from the partial response in terms of duration of response and survival.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Important prognostic value of standardized objective criteria of response in stage D2 prostatic carcinoma. 276 14

One hundred fifty-four patients with clinical stage D2 prostate cancer with no previous endocrine therapy or chemotherapy received the combination therapy with the pure antiandrogen Flutamide and the LHRH agonist [D-Trp]LHRH ethylamide for an average of 22 months (3 to 49). The objective response to the treatment was assessed according to the criteria of the US NPCP. There was a 6.3-fold increase (29.2 versus 4.6%) in the percentage of patients who achieved a complete response as compared to the results achieved in 5 recent studies limited to removal (orchiectomy) or blockade (DES or Leuprolide) of testicular androgens. Only 4.5% of patients did not respond to the combination therapy as compared to an average of 18% by standard therapy. The duration of response is also significantly increased in the patients who received the combination therapy while the death rate was decreased by approximately 2-fold between 2 and 3 years of treatment. The marked (6.3-fold) improvement in the rate of complete objective responses coupled with the 4-fold decrease in the number of non responders, the increased duration of the positive responses and the 2-fold decrease in the death rate at 2 to 3 years of treatment are obtained with the combination therapy using Flutamide and castration with no or minimal secondary effects. In addition, two hundred nine patients with biopsy-proven stage D2 prostatic adenocarcinoma showing disease progression after orchiectomy, DES or an LHRH agonist used alone received the combination therapy with the pure antiandrogen Flutamide. In patients treated with DES, the estrogen was replaced by the LHRH agonist [D-Trp6]LHRH ethylamide. Objective response to therapy was also assessed according to the criteria of the US NPCP. Thirteen patients (6.2%) had a complete response to treatment while partial and stable responses were achieved in 20 (9.6%) and 39 (18.7%) patients, respectively, for a total objective response rate of 34.5%. The mean duration of response was 24 months. While, in the non responders, the median survival was 8.13 months with a 17% probability of survival at 2 years, the probability of survival of patients who showed partial and stable responses at 2 years was 87 and 67%, respectively. All patients who achieved a complete response are still alive. Considering the excellent tolerance coupled with an objective response observed in 34.5% of the patients, the combination therapy with Flutamide and castration (surgical or LHRH agonist) appears to be the treatment of choice for prostate cancer patients in relapse after standard endocrine therapy.
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PMID:Combination therapy with flutamide and castration (orchiectomy or LHRH agonist): the minimal endocrine therapy in both untreated and previously treated patients with advanced prostate cancer. 328 66


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