Phase II study of transdermal estradiol in androgen-independent prostate carcinoma

Thrombophilia and hormonal therapy in transgender persons: A literature review and case series

Background: Venous thromboembolism (VTE) is a rare side effect of hormonal therapy in transgender persons. Prothrombotic genetic variants can increase this risk. For this reason, previous VTE and/or genetic thrombophilia may be considered by some as contraindications to hormonal treatment. Aim: To formulate directions for clinical practice about the indications for thrombophilia screening and when to consider combination therapy of therapeutic anticoagulation and hormonal treatment as a safe alternative to withholding hormonal treatment. Methods: We conducted a literature search and describe a case series. All adult patients with gender dysphoria and a known prothrombotic genetic variant or history of VTE were invited by letter to participate in this study. Results: In our center, thrombophilia screening before start of hormonal treatment was restricted to those with a personal or family history of VTE. Sixteen individuals with a history of VTE and/or an underlying prothrombogenic condition were described. The time of follow up varied from 4 months to 20 years. Seven trans women had a positive thrombophilia screening (2 Factor V Leiden (FVL), 1 FVL + anticardiolipin antibodies, 1 FVL + high Factor VIII coagulant activity, 1 protein C deficiency, 1 prothrombin mutation, 1 positive lupus anticoagulant). Three trans women experienced an unprovoked VTE after start of hormonal therapy of which one lead to a positive thrombophilia screening. One VTE event in a trans woman was assumed to be provoked by surgery. Five trans men were identified with a prothrombogenic mutation (3 FVL, 1 protein C deficiency, 1 prothrombin mutation). One trans man, with a negative thrombophilia screen, experienced multiple provoked VTE events before start of hormonal therapy. Conclusion: Based on our literature review and case series we offer guidance when confronted with patients with previous VTE and/or genetic thrombophilia requesting hormonal interventions.

The Use of Transdermal Estrogen in Castrate-resistant, Steroid-refractory Prostate Cancer

BACKGROUND

Androgen-deprivation therapy is the mainstay of treatment for metastatic prostate cancer. Corticosteroids and estrogens are also useful agents in castration-resistant prostate cancer (CRPC). However, oral estrogens are associated with thromboembolic events, which limits their use, and transdermal estrogens may offer a safer alternative. This study was carried out to determine the safety and effectiveness of transdermal estrogens in CRPC.

PATIENTS AND METHODS

Forty-one patients with CRPC and steroid-resistant prostate cancer were eligible for this dose-escalation study of transdermal estradiol. A starting dose of 50 mcg/24 hours was applied and increased if prostate-specific antigen (PSA) rose > 5 ng/mL in steps to 300 mcg/24 hours. The primary endpoint was PSA response, and secondary outcomes included incidence of thromboembolic events and progression-free survival. Patients who progressed were offered diethylstilbestrol.

RESULTS

Five (13%) of 40 patients had > 50% PSA reduction for at least 1 month at any transdermal estradiol dose. No venous-thromboembolic events were observed, and responses plateaued at 200 mcg/24 hours. A correlation between PSA response and rising sex hormone binding globulin was seen. Fifty percent of patients subsequently responded to low-dose diethylstilbestrol.

CONCLUSION

Transdermal estradiol appears to be a low toxicity treatment option to control CRPC after failure of steroid therapy. Modulation of sex hormone binding globulin by transdermal estradiol may be one mechanism of action of estrogens on CRPC. Oral estrogens remain effective after the use of transdermal estradiol.

Thrombotic issues in transgender medicine: A review

Clinicians, including hematologists, are more frequently encountering transgender individuals in practice; however, most lack training on the management and complications of transgender medicine. Hormonal therapy forms the backbone of medical interventions for patients undergoing gender transition. While supplementing an individual's intrinsic sex hormone is associated with a variety of hematologic complications including increased rates of venous thrombosis, cardiovascular events, erthyrocytosis, and malignancy, the risks of supplementing with opposing sex hormones are not well understood. Data on the hematologic complications of these therapies are accumulating but remain limited, and clinicians have little experience with their management. This review highlights the current interventions available in transgender medicine and related potential hematologic complications, and it suggests simple, evidence-based management going forward. Am. J. Hematol. 92:204-208, 2017. © 2016 Wiley Periodicals, Inc.

Influence of dioxin exposure upon levels of prostate-specific antigen and steroid hormones in Vietnamese men

Most studies on the relationship between Agent Orange and prostate cancer have focused on US veterans of the Vietnam War. There have been few studies focusing on the relationship between levels of prostate-specific antigen (PSA) and dioxins or steroid hormones in Vietnamese men. In 2009-2011, we collected blood samples from 97 men who had resided in a "dioxin hotspot" and 85 men from a non-sprayed region in Vietnam. Then levels of PSA, dioxins, and steroid hormones were analyzed. Levels of most dioxins, furans, and non-ortho polychlorinated biphenyls were higher in the hotspot than those in the non-sprayed region. Levels of testosterone, dehydroepiandrosterone, and estradiol differed significantly between the hotspot and the non-sprayed region, but there were no correlations between levels of PSA and steroid hormones and dioxins in either of the two regions. Our findings suggest that PSA levels in Vietnamese men are not associated with levels of dioxin or steroid hormones in these two regions.

Diethylstilboestrol for the treatment of prostate cancer: past, present and future

The aim of this review was to discuss the most recent data from current trials of diethylstilboestrol (DES) to identify its present role in advanced prostate cancer treatment as new hormonal therapies emerge. The most relevant clinical studies using DES in castration-refractory prostate cancer (CRPC) were identified from the literature. The safety, efficacy, outcomes and mechanisms of action are summarized. In the age of chemotherapy this review highlights the efficacy of oestrogen therapy in CRPC. The optimal point in the therapeutic pathway at which DES should be prescribed remains to be established.

Transdermal estradiol in castrate and chemotherapy resistant prostate cancer

BACKGROUND

Given prior studies demonstrating the marked clinical activity of oral estrogens in prostate cancer, more recent data demonstrating the safety of transdermal estradiol, and the renewed interest in targeting testosterone metabolism and androgen receptor pathways, we report the results of a trial of transdermal estradiol in advanced heavily pre-treated castrate and chemotherapy refractory patients.

MATERIAL/METHODS

Patients with prostate cancer progressing after androgen ablation therapy and chemotherapy were treated with transdermal estradiol patches (0.4 mg per 24 hours total) applied weekly and assessed for tolerability and biochemical activity.

RESULTS

Twenty-two patients were treated on study with all patients evaluable for safety and 20 patients evaluable for response. All patients had aggressive and resistant disease, as demonstrated by a median PSA of 170 ng/mL (range 14 to 5030 ng/mL), with more than 60% having been treated with two or more prior chemotherapy regimens, and 20% with visceral disease. Nine patients had a decrease in PSA, of which two patients had a PSA response defined as a decline in PSA by 50%. Therapy was well tolerated and no thrombotic events were observed.

CONCLUSIONS

In heavily pre-treated patients with advanced castrate and chemotherapy refractory metastatic prostate cancer, transdermal estradiol was safe and had biochemical activity. These data support further studies to understand if transdermal estradiol can be useful following multiple standard therapies.

Estrogens and prostate cancer: etiology, mediators, prevention, and management

The mainstay targets for hormonal prostate cancer (PCa) therapies are based on negating androgen action. Recent epidemiologic and experimental data have pinpointed the key roles of estrogens in PCa development and progression. Racial and geographic differences, as well as age-associated changes, in estrogen synthesis and metabolism contribute significantly to the etiology. This article summarizes how different estrogens/antiestrogens/estrogen mimics contribute to prostate carcinogenesis, the roles of the different mediators of estrogen in the process, and the potentials of new estrogenic/antiestrogenic compounds for prevention and treatment of PCa.

Estradiol suppresses tissue androgens and prostate cancer growth in castration resistant prostate cancer

Background

Estrogens suppress tumor growth in prostate cancer which progresses despite anorchid serum androgen levels, termed castration resistant prostate cancers (CRPC), although the mechanisms are unclear. We hypothesize that estrogen inhibits CRPC in anorchid animals by suppressing tumoral androgens, an effect independent of the estrogen receptor.

Methods

The human CRPC xenograft LuCaP 35V was implanted into orchiectomized male SCID mice and established tumors were treated with placebo, 17β-estradiol or 17β-estradiol and estrogen receptor antagonist ICI 182,780. Effects of 17β-estradiol on tumor growth were evaluated and tissue testosterone (T) and dihydrotestosterone (DHT) evaluated by mass spectrometry.

Results

Treatment of LuCaP 35V with 17β-estradiol slowed tumor growth compared to controls (tumor volume at day 21: 785 ± 81 mm³ vs. 1195 ± 84 mm³, p = 0.002). Survival was also significantly improved in animals treated with 17β-estradiol (p = 0.03). The addition of the estrogen receptor antagonist ICI 182,780 did not significantly change survival or growth. 17β-estradiol in the presence and absence of ICI 182,780 suppressed tumor testosterone (T) and dihydrotestosterone (DHT) as assayed by mass spectrometry. Tissue androgens in placebo treated LuCaP 35V xenografts were; T = 0.71 ± 0.28 pg/mg and DHT = 1.73 ± 0.36 pg/mg. In 17β-estradiol treated LuCaP35V xenografts the tissue androgens were, T = 0.20 ± 0.10 pg/mg and DHT = 0.15 ± 0.15 pg/mg, (p < 0.001 vs. controls). Levels of T and DHT in control liver tissue were < 0.2 pg/mg.

Conclusions

CRPC in anorchid animals maintains tumoral androgen levels despite castration. 17β-estradiol significantly suppressed tumor T and DHT and inhibits growth of CRPC in an estrogen receptor independent manner. The ability to manipulate tumoral androgens will be critical in the development and testing of agents targeting CRPC through tissue steroidogenesis.

Androgen deprivation therapy: progress in understanding mechanisms of resistance and optimizing androgen depletion

Androgen deprivation therapy remains a critical component of treatment for men with advanced prostate cancer, and data support its use in metastatic disease and in conjunction with surgery or radiation in specific settings. Alternatives to standard androgen deprivation therapy, such as intermittent androgen suppression and estrogen therapy, hold the potential to improve toxicity profiles while maintaining clinical benefit. Current androgen deprivation strategies seem to incompletely suppress androgen levels and androgen-receptor-mediated effects at the tissue level. Advances in the understanding of mechanisms that contribute to castration-resistant prostate cancer are leading to rationally designed therapies targeting androgen metabolism and the androgen receptor. The results of large trials investigating the optimization of primary androgen deprivation therapy, including evaluation of intermittent androgen suppression and phase III studies of novel androgen synthesis inhibitors, such as abiraterone acetate, are eagerly awaited.

Effects of hormonal treatment on lipids in patients with cancer

Patients with malignant disease may need hormonal therapy as primary or adjuvant treatment or for palliation. Oestrogens usually decrease serum levels of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C), increase high density lipoprotein cholesterol (HDL-C) concentration, but induce an elevation in serum triglyceride (TG) levels. Progestogens in the short-term decrease TC, LDL-C and HDL-C concentrations, and increase TG levels. In long-term treatment, progestogens usually have a small impact on lipid profile. Tamoxifen induces a decrease in TC and LDL-C levels, an increase in TG concentration, whereas either an increase, decrease or no change has been reported for HDL-C levels. Aromatase inhibitors induce an elevation, reduction or no change in lipid variables. These results depend mainly on the trial design, i.e. whether patients received prior treatment with tamoxifen or not and the duration of therapy. Gonadorelin analogues increase all lipid variables, but LDL-C alterations are usually non-significant. Anti-androgens usually decrease TC, LDL-C and HDL-C levels, whereas TG alterations vary. Information regarding the effects on lipid profile of somatostatin analogues is available almost exclusively in patients with acromegaly. In these patients somatostatin analogues usually induce no change or a decrease in TC and LDL-C levels, whereas they increase HDL-C and decrease TG serum concentrations. Oncologists should consider the lifestyle changes, and if needed hypolipidemic treatment, used to lower cardiovascular risk in non-cancer patients. Tamoxifen may rarely cause serious TG-related side effects, like acute pancreatitis.

The social context for psychological distress from iatrogenic gynecomastia with suggestions for its management

INTRODUCTION

Gynecomastia (breast development in males) is a side effect of androgen deprivation therapy (ADT) for prostate cancer (PCa). Medical interventions to prevent or treat gynecomastia carry risk of additional detrimental side effects. However, untreated gynecomastia can be physically uncomfortable and psychologically distressing. Shame from gynecomastia can lead patients to stop otherwise beneficial exercise.

AIMS

Our first aim is to explore the social context for gynecomastia and how it is interpreted by men with the condition, as well as by others, both male and female. Subsequently, we use our understanding of why gynecomastia is psychologically distressing to propose psychosocial interventions that could help men accept this side effect of ADT.

METHODS

We draw on academic literature, media accounts, and web-based testimonials from men with gynecomastia, to understand how gynecomastia is perceived by both patients and the medical community. We examine these resources in light of gynecomastia's impact on sex roles, sexuality, and gender identity issues.

MAIN OUTCOME MEASURES

By exploring what breasts in a male mean to the individual, we produce an understanding of the social context for distress from gynecomastia. From this understanding, we derive hypotheses about who might be most distressed from gynecomastia and strategies for alleviating this distress.

RESULTS

The shame and stigma of gynecomastia is linked to the objectification of women. We suggest that men fear that their breasts will marginalize and subordinate them within gender hierarchies. There is little evidence that breasts on a male erotically attract either men or women. Novel options for living with gynecomastia are contrasted with medicalized strategies including mastectomy.

CONCLUSION

Assessment instruments need to be developed to identify patients most likely to experience distress from gynecomastia and seek out medical interventions. Surgical, radiological, or pharmacological interventions may not be universally necessary if greater acceptance of gynecomastia is made available through psychosocial support programs. For example, PCa patients may learn to accept gynecomastia through reconceptualizing their breasts as autoerotic. Support programs modeled on those of the breast cancer community, including Encore and dragon boat racing, may also help to build communities to serve patients with gynecomastia while defending individuals against shame, isolation, and loss of self-esteem.

Expression of Nkx3.1 enhances 17beta-estradiol anti-tumor action in PC3 human prostate cancer cells

AIM

To explore whether the anti-tumor action of 17beta-estradiol is enhanced by re-expression of the homeodomain transcription factor Nkx3.1 in PC3 human prostate cancer cells.

METHODS

PC3 cells were stably transfected with pcDNA3.1-Nkx3.1-His vector, which carries a full-length cDNA of human Nkx3.1. The PC3 cells stably transfected with vector pcDNA3.1 were set as a control. The expression of Nkx3.1 protein in the cells was confirmed by Western blot analysis. The effect of Nkx3.1 on cell proliferation of PC3 cells was examined with MTT assay. The antiproliferative and apoptotic effects of 17beta-estradiol alone or in combination with Nkx3.1 were estimated on PC3 cells by using MTT growth tests and flow cytometric analyses. The expression of apoptosis-related proteins was analyzed using Western blotting.

RESULTS

The plasmid carrying Nkx3.1 gene induced high expression of Nkx3.1 protein in PC3 cells. The re-expression of exogenous Nkx3.1 did not cause a significant reduction in cellular proliferation, whereas the expression of Nkx3.1 enhanced the 17beta-estradiol anti-proliferative effect in PC3 cells. Nkx3.1 expression promoted 17beta-estradiol-induced apoptosis of PC3 cells, as shown by analysis of Bcl-2, Bax, Caspase-3 and poly (ADP-ribose) polymerase expression.

CONCLUSION

The present study demonstrates that re-expression of Nkx3.1 enhances 17beta-estradiol anti-tumor action in PC3 human prostate cancer cells. The in vitro study suggests that re-expression of Nkx3.1 is worthy of further consideration as an adjuvant treatment of androgen independent prostate cancer with estrogen anti-tumor therapies.

Transdermal oestrogen therapy as a second-line hormonal intervention in prostate cancer: a bad experience

OBJECTIVE

To compare transdermal oestrogen with oral diethylstilbestrol (DES) as a second- or third-line hormonal therapy in the treatment of prostate cancer.

PATIENTS AND METHODS

In all, 32 assessable patients who, having already had a relapse on at least one line of hormonal therapy, received transdermal oestrogen therapy as an alternative to oral DES, when DES became unavailable.

RESULTS

Whereas DES had controlled the prostate-specific antigen (PSA) level for a median of 29 weeks in a group of 15 patients in remission, all but one had an increase in PSA level (median 86% increase above the starting PSA level) within a median of 8 weeks after introducing transdermal therapy. This increase was reversed in seven of the 12 patients who recommenced DES therapy.

CONCLUSION

Although the use of transdermal oestrogen is currently attracting enthusiasm as a first-line treatment for prostate cancer, these results show that for second- or third-line therapy further cautious research with careful monitoring is necessary.

Estrogen receptor beta (ERbeta) and inhibition of prostate cancer cell proliferation: studies on the possible mechanism of action in DU145 cells

Estrogen receptor beta (ERbeta) plays a protective role against uncontrolled cell proliferation. ERbeta is lost during prostate cancer (CaP) progression suggesting its direct involvement in contrasting tumor proliferation in this disease; however, the molecular mechanism at the basis of this effect has not been clearly defined yet. Possible molecular targets of ERbeta were assessed in DU145 cells, a CaP cell line expressing only ERbeta. Cells treated from 1 to 9 days with different doses of estradiol or diarylpropionitrile (DPN, an ERbeta-selective agonist) show a time-dependent decrease in cell proliferation. The reduced proliferation rate is accompanied by the stimulation of ERbeta expression and the increase of cyclin-dependent kinase inhibitor p21. We demonstrate that the endogenous ERbeta is one of the mediator of the antiproliferative action of estrogens enhancing the synthesis of molecules such as p21 that control cell cycle, an effect amplified by the autoregulation of ERbeta expression. Our observations suggest that CaP, when expressing a functional ERbeta, might be sensitive to the antiproliferative action of estrogens; therefore, ERbeta specific agonists might be valid candidates for new pharmacological approaches to this disease.

Diethylstilbestrol and docetaxel

BACKGROUND

The addition of diethylstilbestrol to docetaxel modified tubulin composition and improved the response of prostate cancer to chemotherapy in preclinical models. An attempt was made to recapitulate the observations in a clinical trial.

METHODS

Twenty-nine patients with progressive, metastatic, chemotherapy-naive androgen-independent prostate cancer were treated with diethylstilbestrol 1 mg daily and 5 mg on the day before docetaxel and docetaxel 36 mg/m(2) intravenously weekly for 3 weeks of a 4-week cycle. Prophylactic anticoagulation was used in all patients. Patients were assessed by prostate-specific antigen (PSA) monthly and computed tomography (CT) and bone scans every 3 cycles. The Response Evaluation Criteria in Solid Tumors (RECIST) criteria and PSA decline by >50% maintained for 4 weeks were used to assess activity.

RESULTS

The median age was 68 years (range, 56-84 years), Southwest Oncology Group performance status 0 (score range, 0-2), alkaline phosphatase 120 U/L (range, 49-523), hemoglobin (Hgb) 12.6 g/dL (range, 9.2-16.3), PSA 66 ng/dL (range, 4-1962). The median number of cycles administered was 6. Soft tissue metastases were present in 51% of patients and bone metastases in 93%. Twenty-nine patients are evaluable for response. Of these, 20 patients (69%, 95% confidence interval [CI], 49%-85%) had a PSA decline of >50% and the PSA declined by >90% in 12 patients (41%, 95% CI, 23.1%-58.9%). Of 15 patients with measurable disease, 6 (40%, 95% CI, 23.5%-61%) had a partial response. Median time to progression was 6 months (range, 3-19 months). Fifteen patients (51%) suffered grade 3/4 toxicity. Two patients died of causes unrelated to therapy and another died from a steroid-induced ulcer. Six patients developed thrombosis and of those tested 75% had Factor V mutations. Pretreatment PSA, performance status, Hgb, and alkaline phosphatase had no impact on the likelihood of response.

CONCLUSIONS

The combination of diethylstilbestrol and docetaxel produces a significant level of activity, measured by PSA decline and measurable disease response rate, and except for venous thrombosis the toxicity appears similar to that seen with docetaxel plus prednisone. These results suggest that tubulin modulation with diethylstilbestrol may improve the therapeutic efficacy of docetaxel and the combination is worthy of further study.

Bone Related Events in High Risk Prostate Cancer

PURPOSE

We provide recommendations for defining and treating bone related events in high risk prostate cancer.

MATERIALS AND METHODS

A focused literature review was done.

RESULTS

Men with prostate cancer often have osteoporosis and osteopenia even before initiating androgen deprivation therapy. After starting androgen deprivation therapy they experience accelerated bone loss. Bone mineral density is the most common tool to assess the degree of bone loss, although the use of bone turnover markers for this purpose is being actively explored. Bisphosphonates are effective for increasing bone mineral density and treating osteoporosis. The benefits derived from bisphosphonates should be weighed against the adverse effects, including the risk of osteonecrosis of the jaw. Treatment is indicated in patients with prostate cancer with osteoporosis and it may be considered in patients with osteopenia and/or additional risk factors. The time of initiation of therapy and duration of treatment have not been conclusively established.

CONCLUSIONS

Prolonged androgen deprivation therapy results in bone loss and it has a potential to impact quality of life. Additional research is needed to characterize patients who would benefit from therapy and optimize strategies to prevent osteoporosis.

Parenteral Estrogens for Prostate Cancer: Can a New Route of Administration Overcome Old Toxicities?

Androgen deprivation therapy (ADT) is the mainstay of management of advanced-stage prostate cancer and recently has been shown to improve survival when administered in earlier stages of the disease. The oncologic benefits of ADT might be partially offset, however, by a reduction in quality of life because of adverse effects. In addition to the well-recognized adverse consequences of ADT, recent evidence suggests that ADT is associated with dyslipidemia, impaired glucose metabolism, adverse body compositional changes, and osteoporosis. Therefore, there is a pressing need to develop less toxic forms of ADT. A novel approach to this problem is the use of estrogen to induce androgen suppression. Whereas oral estrogen therapy is known to be associated with thromboembolic complications, studies of parenteral estrogen in men with prostate cancer suggest that the use of parenteral estrogen achieves target androgen suppression, does not adversely affect prothrombotic protein levels, and is not associated with adverse metabolic, skeletal, and body compositional changes when compared with conventional ADT. Herein, we review the data for parenteral estrogen use in prostate cancer, the antineoplastic mechanisms of action of estrogen in prostate cancer, the potential advantages of parenteral estrogen compared with conventional ADT, and the remaining barriers in the use of parenteral estrogen in prostate cancer.

Recent progress in hormonal therapy for advanced prostate cancer

PURPOSE OF REVIEW

Primary androgen deprivation therapy and secondary hormonal therapy remain the cornerstones of treatment for advanced prostate cancer. This review outlines the basic evidence for use of hormonal therapy while highlighting major research developments made in the past year.

RECENT FINDINGS

Recent research on androgen deprivation therapy has suggested that patients with high-risk features may have longer metastasis-free survival with early initiation of androgen deprivation therapy. Fracture risk has been shown to be significantly increased in patients on androgen deprivation therapy and is correlated with duration of treatment. In the treatment of androgen-independent prostate cancer, oral premarin has been shown to induce of prostate specific antigen responses more than 50% in 32% of patients, though thromboembolism remains a risk despite prophylactic low-dose warfarin. Transdermal estradiol has been associated with virtually no cardiovascular toxicity, but induced of prostate specific antigen responses more than 50% in only 12.5% of patients. Clinical studies of nilutamide, flutamide, and ketoconazole have further clarified efficacy of these secondary hormonal treatments.

SUMMARY

Optimal timing of androgen deprivation therapy awaits the results of randomized trials, but available evidence indicates that patients with high-risk features may benefit from early androgen deprivation therapy. New estrogen-based therapies have shown promising efficacy in the treatment of androgen-independent prostate cancer, with significantly less cardiovascular toxicity than traditional estrogens.

Testosterone loss and estradiol administration modify memory in men

PURPOSE

Little is known about the effect of androgen deprivation therapy on the brain despite the fact that sex steroid receptors are abundant in cortical brain regions that mediate memory and other cognitive functions. We characterized the impact of androgen deprivation and of subsequent estradiol therapy on the long-term and working memory of patients with prostate cancer.

MATERIALS AND METHODS

Long-term memory (immediate and delayed paragraph recall tests), working memory (SOP and Trails tests) and Profile of Mood States were assessed at baseline and 4 weeks later in 18 patients with androgen independent prostate cancer beginning second line hormonal therapy with transdermal estradiol 0.6 mg/24 hours. The same assessments were performed in 2 age matched control groups of 18 patients with prostate cancer undergoing androgen deprivation continuing on hormonal therapy and 17 community dwelling healthy men.

RESULTS

Immediate and delayed verbal memory were significantly worse in patients with prostate cancer on androgen deprivation than in age matched healthy controls. In addition, men with prostate cancer took more time to complete the Trails A task, indicating slower processing speed, but did not differ significantly from healthy controls in working memory tasks. In individual repeated measures analyses, verbal memory performance improved with estradiol therapy but did not change in the 2 control groups.

CONCLUSIONS

Sex steroid loss and replacement have effects on specific cognitive processes in older men. Furthermore, estrogen has the potential to reverse the neurotoxic effects on memory performance caused by androgen deprivation.

Hormone refractory prostate cancer: Management and advances

Effective therapeutic options have not existed for prostate cancer progressing after androgen deprivation therapy until very recently. Secondary hormonal manipulations offer marginal benefits. Docetaxel based chemotherapy has been demonstrated to extend survival and change the natural history of the disease in two large randomized trials. These studies have provided the impetus to combine docetaxel with novel biologic agents to further consolidate the gains in long-term outcome. With the arrival of exciting agents including vaccines, monoclonal antibodies, bone-targeted drugs, antisense oligonucleotides, anti-angiogenic drugs and small molecule receptor tyrosine kinase inhibitors, the future treatment of prostate cancer appears promising.

Effects of transdermal estrogen on levels of lipids, lipase activity, and inflammatory markers in men with prostate cancer

Androgen deprivation therapy (ADT) for prostate cancer is now used in earlier disease stages and as adjuvant treatment. Recognizing and reducing the toxicity of this therapy, including worsened lipid levels and cardiovascular disease (CVD) risks, has become an important clinical concern. Oral estrogen therapy induces hypogonadism and mitigates many side effects of ADT, but has a high thrombosis risk. Transdermal estrogen therapy (TDE) has a lower thrombosis risk than oral estrogen and may improve CVD risk compared with ADT. This prospective pilot study of 18 men with androgen-independent prostate cancer receiving ADT measured effects of TDE on lipid and inflammatory CVD risk factors before and after 8 weeks of TDE (estradiol 0.6 mg/day). During treatment, estradiol levels rose 17-fold; total cholesterol, LDL cholesterol, and apolipoprotein B levels decreased. HDL2 cholesterol increased, with no changes in triglyceride or VLDL cholesterol levels. Dense LDL cholesterol decreased and LDL buoyancy increased in association with a decrease in HL activity. Highly sensitive C-reactive protein levels and other inflammatory markers did not worsen. Compared with ADT, short-term TDE therapy of prostate cancer improves lipid levels without deterioration of CVD-associated inflammatory markers and may, on longer-term follow-up, improve CVD and mortality rates.

Transdermal application of lovastatin to rats causes profound increases in bone formation and plasma concentrations

INTRODUCTION

Statins are drugs that inhibit HMG Co-A reductase and have been shown to enhance bone formation in vitro and in vivo in rodents. However, the statins currently used for cholesterol-lowering have been selected for their capacity to target the liver where their effects on cholesterol synthesis are mediated and they undergo first pass metabolism. When given in lipid-lowering doses, these agents do not likely reach sufficient blood concentrations to reliably cause substantial increases in bone formation in humans. Moreover, statins are inactivated by cytochrome P450 enzymes, resulting in even less peripheral distribution of the biologically active moieties beyond the liver.

METHOD

To investigate whether an alternate method of administration might produce beneficial effects on bone formation, we administered lovastatin by dermal application to rats to circumvent the first-pass effects of the gut wall and liver.

RESULTS

We found that the statin blood levels measured by HMG Co-A reductase activity were higher, maintained longer and less variable following transdermal application than those following oral administration. Also the increased circulating statin levels were associated with significantly enhanced biological effects on bone. After only 5 days of administration of transdermal lovastatin to rats, there was a 30-60% increase in trabecular bone volume, and 4 weeks later, we observed more than a 150% increase in bone formation rates. There was also a significant increase in serum osteocalcin, a marker of bone formation. We also found that lovastatin administered transdermally produces these profound effects at doses in the range of 1% of the oral dose, without any evidence of the hepatotoxicity or myotoxicity that can occur following oral statin administration. Several doses (0.01-5 mg kg(-1) day(-1)) and dosage schedules were examined, and collectively the data strongly suggest a powerful anabolic effect but with an unusually flat dose-response curve.

CONCLUSION

These results show transdermal application of statins produces greater beneficial effects on bone formation than oral administration does.

Effects of Transdermal Estrogen Replacement Therapy on Cardiovascular Risk Factors

The prevalence of hypertension and cardiovascular disease increases dramatically after menopause in women, implicating estrogen as having a protective role in the cardiovascular system. However, recent large clinical trials have failed to show cardiovascular benefit, and have even demonstrated possible harmful effects, of opposed and unopposed estrogen in postmenopausal women. While these findings have led to a revision of guidelines such that they discourage the use of estrogen for primary or secondary prevention of heart disease in postmenopausal women, many investigators have attributed the negative results in clinical trials to several flaws in study design, including the older age of study participants and the initiation of estrogen late after menopause.Because almost all clinical trials use oral estrogen as the primary form of hormone supplementation, another question that has arisen is the importance of the route of estrogen administration with regards to the cardiovascular outcomes. During oral estrogen administration, the concentration of estradiol in the liver sinusoids is four to five times higher than that in the systemic circulation. This supraphysiologic concentration of estrogen in the liver can modulate the expression of many hepatic-derived proteins, which are not observed in premenopausal women. In contrast, transdermal estrogen delivers the hormone directly into the systemic circulation and, thus, avoids the first-pass hepatic effect.Although oral estrogen exerts a more favorable influence than transdermal estrogen on traditional cardiovascular risk factors such as high- and low-density lipoprotein-cholesterol levels, recent studies have indicated that oral estrogen adversely influences many emerging risk factors in ways that are not seen with transdermal estrogen. Oral estrogen significantly increases levels of acute-phase proteins such as C-reactive protein and serum amyloid A; procoagulant factors such as prothrombin fragments 1+2; and several key enzymes involved in plaque disruption, while transdermal estrogen does not have these adverse effects.Whether the advantages of transdermal estrogen with regards to these risk factors will translate into improved clinical outcomes remains to be determined. Two ongoing clinical trials, KEEPS (Kronos Early Estrogen Prevention Study) and ELITE (Early versus Late Intervention Trial with Estradiol) are likely to provide invaluable information regarding the role of oral versus transdermal estrogen in younger postmenopausal women.