Oestrogen dosage in prostatic cancer: the threshold effect?

Parenteral oestrogen in the treatment of prostate cancer: a systematic review

The objectives of this study were to assess the effectiveness and safety of parenteral oestrogen in the treatment of prostate cancer, and to examine any dose relationship. A systematic review was undertaken. Electronic databases, published paper and internet resources were searched to locate published and unpublished studies with no restriction by language or publication date. Studies included were randomised controlled trials of parenteral oestrogen in patients with prostate cancer; other study designs were also included to examine dose-response. Study selection, appraisal, data extraction and quality assessment were performed by one reviewer and independently checked by another. Twenty trials were included in the review. The trials differed with regard to the included patients, formulation and dose of parenteral oestrogen, comparator used, outcome measures reported and the duration of follow-up. The results provide no evidence to suggest that parenteral oestrogen, in doses sufficient to produce castrate levels of testosterone, is less effective than luteinising hormone-releasing hormone (LHRH) or orchidectomy in controlling prostate cancer, or that it is consistently associated with an increase in cardiovascular mortality. Further well-conducted trials of parenteral oestrogen are required. A pilot randomised controlled trial comparing transdermal oestrogen to LHRH analogues in men with locally advanced or metastatic prostate cancer is underway in the United Kingdom.

Therapy Insight: parenteral estrogen treatment for prostate cancer—a new dawn for an old therapy

Oral estrogens were the treatment of choice for carcinoma of the prostate for over four decades, but were abandoned because of an excess of cardiovascular and thromboembolic toxicity. It is now recognized that most of this toxicity is related to the first pass portal circulation, which upregulates the hepatic metabolism of hormones, lipids and coagulation proteins. Most of this toxicity can be avoided by parenteral (intramuscular or transdermal) estrogen administration, which avoids hepatic enzyme induction. It also seems that a short-term but modest increase in cardiovascular morbidity (but not mortality) is compensated for by a long-term cardioprotective benefit, which accrues progressively as vascular remodeling develops over time. Parenteral estrogen therapy has the advantage of giving protection against the effects of andropause (similar to the female menopause), which are induced by conventional androgen suppression and include osteoporotic fracture, hot flashes, asthenia and cognitive dysfunction. In addition, parenteral estrogen therapy is significantly cheaper than contemporary endocrine therapy, with substantive economic implications for health providers.

Markers of the metastatic phenotype in prostate cancer

Metastatic malignant disease is the single most common cause of treatment failure and subsequent mortality of most human malignancies, including prostate cancer. Presently, cells expressing the metastatic phenotype cannot be identified within a primary tumor population. Hence, accurate assessment of the likely behavior of an individual primary malignancy cannot be made at the time of diagnosis. The studies now reported have been aimed at identifying some of the features that may be associated with the metastatic phenotype of prostatic cancer. Insight into those factors that may be involved in prostate cancer metastasis has been gained from a variety of experimental approaches as well as study of intact human prostate cancers.

Effects of progesterone administration on follicle-stimulating hormone and prolactin release in estrogen treated eugonadal adult men

In order to investigate the modulatory effect of steroids on FSH secretion in vivo, we studied 16 human males, aged 51-81 years, affected by prostatic carcinoma. They were given estradiol or E2 plus progesterone (P), added at different times during E2 treatment. Daily blood samples were collected in order to determine LH, FSH, and PRL levels; moreover, blood samples were collected at 2 h intervals for 12 h on the day of P administration. We observed the expected biphasic effect on LH secretion, whereas daily basal FSH levels, during E2 treatment, decreased gradually and progressively from the first day until the end of the study. FSH levels exhibited, after P administration, wide fluctuations, with peak levels observed from 2 to 6 h after P in 4 of 6 patients studied (at 72 h during E2 treatment). A clear trend toward FSH increase was also observed in 3 out of 5 patients in whom P was administrated 96 h after starting E2 administration. In this case, FSH increases were delayed, becoming evident between 8th and 10th h after P injection. Finally, during E2 administration basal PRL levels showed a progressive increase, which was significant in all three groups. In conclusion, these data confirm the biphasic effects of estrogen administration on LH secretion in eugonadal adult human males; while estrogens alone showed an inhibitory effect on FSH secretion, the addition of P induced also a positive action, resulting in a clear FSH peak in some patients tested. The time course of E2 and P administration seems to be critical for the hormone response pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary orchiectomy versus estrogen therapy in advanced prostatic cancer--a randomized study: results after 7 to 10 years of followup

Of 163 new consecutively diagnosed cases of advanced (T3-4 M0 or T04M1) prostatic cancer 13 had contraindications for estrogen treatment, and the remainder were randomized to orchiectomy (76) or to estrogen treatment (74), consisting of 150 micrograms ethinyl estradiol daily and 80 mg. polyestradiol monthly. During the followup period of 7 to 10 years disease progression was noted in 27 patients (36%) treated with estrogen and 39 (51%) orchiectomized patients. The free of progression survival rate was significantly better (less than 0.05) among the estrogen treated patients but the over-all survival rates after orchiectomy and estrogen treatment were almost identical. A significantly higher frequency of cardiovascular side effects was noted in the estrogen group (23 cases) compared to the orchiectomy group (4 cases). Therefore, estrogen treatment in this form cannot be recommended for the palliative treatment of prostate cancer.