Hormonal effects of high dose medroxyprogesterone acetate treatment in males with renal or prostatic adenocarcinoma

Glucocorticoids and prostate cancer treatment: friend or foe?

Glucocorticoids have been used in the treatment of prostate cancer to slow disease progression, improve pain control and offset side effects of chemo- and hormonal therapy. However, they may also have the potential to drive prostate cancer growth via mutated androgen receptors or glucocorticoid receptors (GRs). In this review we examine historical and contemporary use of glucocorticoids in the treatment of prostate cancer, review potential mechanisms by which they may inhibit or drive prostate cancer growth, and describe potential means of defining their contribution to the biology of prostate cancer.

Use of DHEA in a patient with advanced prostate cancer: a case report and review

Dehydroepiandrosterone (DHEA) is being evaluated in the basic science laboratories as a potential treatment for adenocarcinomas, with some initial promise for success. However DHEA can be metabolically converted to androgenic compounds, possessing unwanted side effects. A patient with advanced prostate cancer with progressive symptomatology was treated with DHEA after other treatment regimens failed. Many of his symptoms improved on DHEA therapy, but his cancer also flared dramatically during treatment. His previous hormonally unresponsive cancer subsequently responded transiently to third-line hormonal therapy with diethylstilbestrol (DES). Adrenal precursor molecules such as DHEA may have significant therapeutic benefits in a number of diseases of the elderly, however their utility may be limited by potential androgenic side effects including endocrine epithelial cell growth. The development of analogue compounds with less conversion to androgenic metabolites should be considered, as molecules such as DHEA are more widely tested and utilized clinically.

Cellular changes in prostatic carcinoma after treatment with orchidectomy, estramustine phosphate and medroxyprogesterone acetate

Thirty-three patients with prostatic carcinoma were treated with either estramustine phosphate, orchidectomy or high dose medroxyprogesterone acetate. Therapy response was evaluated by cytological examination of fine needle aspiration biopsies performed before and after 6 weeks treatment. At follow-up, 11 of 14 patients treated with estramustine phosphate had regressive and/or degenerative changes, in 2 patients there were no prostatic carcinoma cells in the smears and in one there was a marked reduction of the number of tumour cells. In 7 of 10 patients treated with orchidectomy there was a marked reduction of the percentage of malignant cells while smears from 3 patients were unchanged. In the 8 patients treated with high dose medroxyprogesterone acetate the cell patterns were unmodified compared with before treatment. We conclude that, in contrast to the lack of effect of treatment with medroxyprogesterone acetate, treatment with orchidectomy and especially estramustine phosphate caused morphologic cellular changes in prostatic carcinoma.

Effects of estrogens and progestogens on the membrane permeability and growth of human prostatic carcinoma cells (PC-3) in vitro

The effects of estrogens and progestogens in the management of prostatic adenocarcinoma are generally believed to be related to their suppressive effect on the hypothalamic-pituitary-testicular axis, but other mechanisms have also been suggested. The present study was designed to investigate if an androgen-insensitive human prostatic cancer cell line (PC-3) is sensitive to estrogens or progestogens and to elucidate possible mechanisms of action. Both estrogens and progestogens in high doses (10(-5) M) suppressed tumor cell growth. At these high doses medroxyprogesterone acetate (MPA) most effectively reduced the uptake of 86rubidium chloride, indicating the strongest effect on ion transport and membrane permeability. Effects on rubidium transport were also seen after estrogen treatment. It is suggested that estrogens and progestogens have direct cytotoxic effects on prostatic carcinoma cells in vitro, possibly by an effect on the cell membrane.

Experiences with doxo/epirubicin and medroxyprogesterone acetate (MPA) in prostatic cancer

Maximal androgen blockade (MAB) has been reported to prolong the time to progression and the duration of survival in metastatic prostatic cancer. The addition of epirubicin to MAB in such patients seems to improve the therapeutic results further. The beneficial effect of combining castration with epirubicin in metastatic cases appears questionable. In comparing the time to progression in patients treated with MAB +/- epirubicin versus castration +/- epirubicin or estramustine, many studies reveal similar figures. Whether the results after treatment are actually improved remains controversial. In hormone-refractory cases, medroxyprogesterone acetate (MPA) alone seems superior to estramustine or prednisolone treatment. Combining MPA and epirubicin improves the results, but even if the improvement is of clinical value, it is nonetheless of limited magnitude.

Medroxyprogesterone acetate decreases the sexual activity of male cynomolgus monkeys (Macaca fascicularis): an action on the brain?

Medroxyprogesterone acetate (MPA), a synthetic progestin with androgen-depleting activity, is used to treat the deviant behavior of male sex offenders. In male cynomolgus monkeys, MPA reduces plasma testosterone (T) levels and sexual behavior, but the behavioral effects are clearly different from those of surgical castration. Because MPA is selectively taken up in unchanged form by the nuclei of neurons in the hypothalamus and preoptic area of male cynomolgus monkeys, and because it interferes with the uptake of T throughout the brain and pituitary gland, we have proposed that the behavioral effects of MPA may be mediated by brain mechanisms regulating sexual motivation that are relatively independent of circulating T levels. To test this hypothesis, eight castrated male cynomolgus monkeys bearing Silastic T implants SC were each observed during 60 min behavior tests with an ovariectomized, estrogen-treated female throughout three 4-week periods separated by 4-week periods without testing. After the first 4 weeks of testing, males received weekly IM injections of 40 mg MPA (six males) or vehicle (two males); the dose of MPA being equivalent on a body weight basis to those used clinically. Although plasma T was maintained in the upper range for intact males throughout the study, MPA treatment resulted in significantly decreased ejaculations and mounting attempts by weeks 5-6. These results demonstrated that the inhibitory effects of MPA on male behavior were independent of the reduction of plasma T levels, which points to a direct action on brain mechanisms controlling male sexual behavior.

Treatment of rat prostatic adenocarcinoma with medroxyprogesterone acetate (MPA): effects on growth and morphology

Rats bearing the Dunning R3327H prostatic carcinoma were castrated and supplemented with testosterone propionate. These rats were then treated with estradiol benzoate or medroxyprogesterone acetate alone or in combination with estradiol. During the treatment period of six weeks, the growth rate of the prostatic tumors was measured. At the end of the treatment period the morphology of the tumors was also studied. It was found that medroxyprogesterone acetate is as effective as estradiol in inhibiting the growth of the Dunning prostatic carcinoma and that the combination of medroxyprogesterone acetate and estradiol was more efficient in that respect than estradiol alone. Morphometric evaluation of the tumor epithelium and stroma showed a decrement of epithelial growth in all treatment groups, while the groups treated with medroxyprogesterone acetate, both alone or in combination with estradiol, also showed an inhibited growth of the tumor stroma. It was concluded that medroxyprogesterone acetate probably has direct inhibitory effects on prostatic tumor cells in the Dunning model and that medroxyprogesterone acetate may act in an additive manner with estradiol.

Medroxyprogesterone acetate and the nuclear uptake of testosterone and its metabolites by brain, pituitary gland and genital tract in male cynomolgus monkeys

The synthetic progestin, medroxyprogesterone acetate (MPA), is used to treat male sex offenders, and it is also suppresses sexual activity in male monkeys. To examine the possibility that MPA may act as an anti-androgen in the primate brain, 4 intact male cynomolgus monkeys were given MPA (40 mg i.m.) once a week for 16 weeks, while 4 control males received i.m. injections of vehicle. All males were then castrated and 3 days later were given 3 mCi [3H]testosterone ([3H]T) i.v.; 1 h after injection males were killed, and radioactivity in nuclear pellets obtained from the hypothalamus (HYP), preoptic area (POA), amygdala (AMG), septum, pituitary gland and genital tract was analyzed by HPLC. Concentrations of [3H]T and [3H]dihydrotestosterone in nuclear pellets were 65-96% lower in MPA-treated males than in controls (P less than 0.001), but the aromatized metabolite, [3H]estradiol, which was the major form of radioactivity present in nuclear pellets from HYP, POA and AMG, was unchanged. There were no differences in concentrations of [3H]T in supernatants from the tissues of MPA-treated and control males. Because the reduced nuclear uptake of androgen in brain occurred in males whose androgen-dependent behavior had been suppressed by MPA treatments, it is proposed that MPA may have anti-androgenic effects at the level of the cell nucleus in brain regions that control behavior.

Medroxyprogesterone acetate lowers plasma corticotropin and cortisol but does not suppress anterior pituitary responsiveness to human corticotropin releasing factor

The endocrine action of medroxyprogesterone acetate (MPA) has been claimed to be of a glucocorticoid-like nature. Upon clinical observation, MPA has been shown to improve life quality and overall well-being in patients with advanced breast cancer, renal carcinoma, prostatic carcinoma, and uterine adenocarcinoma. The authors have evaluated MPA endocrine action by the administration of human corticotropin releasing factor (hCRF) in a 90-minute assay in 15 patients with advanced breast cancer or renal cell carcinoma both, before the initiation of oral high-dose MPA treatment (1000 mg MPA) as well as after at least 10 days of therapy. The curves for corticotropin, beta-endorphin, and cortisol responses to hCRF of tumor patients who were tested before the initiation of MPA treatment were parallel to the curves of a healthy control group of probands tested under equal conditions, although at significantly higher respective hormone levels. In patients with malignant disorders assayed after MPA administration, both basal and peak hormone levels were found to be comparable with values obtained in healthy controls. In conclusion, MPA appeared to act at a suprapituitary level since pituitary responsiveness to hCRF was preserved under MPA treatment. Moreover, it appeared that MPA brought the hormonal stress state found in patients with malignant tumors back to normal.

Effects of high dose medroxyprogesterone acetate treatment on antithrombin III and other plasma proteins in males with renal cell or prostatic carcinoma

In 18 patients, 12 with renal cell and 6 with prostatic carcinoma treatment with high dose medroxyprogesterone acetate (MPA) significantly increased serum antithrombin III and haptoglobin concentrations. During treatment the proteins correlated with each others suggesting a response to similar regulatory mechanisms. Levels of orosomucoid, a1-antitrypsin, C1-inhibitor and von Willebrand factor did not change during treatment showing that the increase of haptoglobin was not due to an acute-phase response. The increased antithrombin III levels may have a favourable impact on the frequency of thromboembolic complications during treatment with MPA.