Androgen Repletion Research Articles

Mifepristone (Korlym ®) Use Interferes With Accurate Serum Measurement of Sex Steroids

Introduction: Mifepristone (MFP) aka RU-486/Korlym is a synthetic steroid analog originally developed in 1980 as an abortifacient that is now used in the management of Cushing’s syndrome (CS). It is both a progesterone (PG) and glucocorticoid (GC) receptor blocker. CS is often associated with reproductive functional anomalies including hypogonadism, menstrual irregularities and infertility. Due to its mode of action, measurement of serum PG and/or cortisol in patients on MFP are inaccurate indices of systemic PG and/or GC deficiency or excess. However, the potential impact of MFP use on other serum steroid assays has not been widely studied. We report the case of a 55 yr old man on treatment with MFP for adrenal CS found to have striking artefactual changes in serum androgen and estrogen levels. Case Summary: A 55 yr old African American man was referred with poorly controlled type 2 diabetes, hypertension, hyperlipidemia, obesity and untreated hypogonadism. He had a 3.2cm left adrenal incidentaloma associated with adrenal CS and he chose medical management rather than surgery. Upon starting MFP at 300mg QD serum total estrogen (by radio-immunoassay; RIA) and estradiol (by chemiluminescence immunoassay; CIA) were markedly elevated while serum total, free, bioavailable testosterone and dihydrotestosterone were all markedly reduced. His HBA1c, weight and energy levels improved on MFP despite these findings. The serum steroid levels normalized to pre-treatment levels after stopping MFP for ~ 4weeks but the changes recurred after restarting therapy. After MFP dose escalation to 300mg BID the serum steroid levels normalized after stopping MFP for ~ 6 weeks. The artefactual low testosterone levels also occured with measurement by equilibrium dialysis but “normal accurate” results were obtained when measured by liquid chromatography-Tandem mass spectrometry (LC-TMS). He remains on MFP 300mg BID without need for androgen repletion. Discussion: With increased use of MFP for CS, indices for tracking its clinical and biochemical effects assume great importance. There are few reports of the possible effects of MFP on estrogen and testosterone serum assays despite its touted low cross reactivity with sex steroids. Our case suggests that the significance, extent and prevalence of artefactual changes on serum sex steroid assays may be underestimated and under- appreciated. Conclusions: Our case of wide disparities in serum estrogen and androgen measures in a patient on MFP indicates that caution needs to be exercised in the interpretation of such results in patients on current MFP therapy. Our clinical observations suggest depending on the dose that a wash out period of 4–6 weeks is required to ensure accurate measures. Studies to ascertain the prevalence of this artefactual effect are needed and it appears testosterone measurement by LC-TMS obviates the testosterone assay artefact.

SAT-466 Cases of Acromegaly and Presumed Prolactinoma in Setting of Empty Sella Syndrome: Presentation and Management Implications

Introduction; Empty Sella syndrome (ESS) is an uncommon finding on brain imaging whose functional significance remains controversial. While sometimes associated with pituitary hypofunction it is far less commonly associated with pituitary hyperfunction syndromes. We present two cases of this; one with acromegaly and one of hyperprolactinemia presumably due to prolactinoma both associated with ESS on brain imaging. Clinical Cases; A 48 yr old man was evaluated on account of reduced libido and chronic fatigue which revealed hypogonadotrophic hypogonadism. Further work up revealed prolactin levels in the 250-300ng/ml range. Brain MRI showed ESS and the rest of the pituitary hormone functional work up was normal. Bone density showed osteopenia and octreotide scan showed no sella enhancement nor other anomalies. When commenced on cabergoline 0.5mg 2 x wkly his prolactin levels normalized over 6 months and the hypogonadism resolved without requiring androgen replacement. A 49 yr old gentleman with long standing hypogonadotrophic hypogonadism on androgen replacement presented with persistent headaches and generalized arthralgias. He had clinical features suggestive of acromegaly including macrocephaly, macroglossia, facial dysmorphia and enlarged hands and feet. Diagnosis was confirmed by elevated IGF-1 (300-400ng/ml range), growth hormone levels and non suppressible growth hormone on Oral glucose tolerance test. No other pituitary functional deficits were found. Brain MRI showed ESS and octreotide scan showed no sella enhancement nor other anomalies. His IGF-1 levels normalized with octreotide LAR 20mg monthly. His androgen repletion also improved with lower testosterone dose requirement along with improvement in headaches and arthralgias though he developed type 2 diabetes. Results and Discussion; Review of our system's clinical records over the prior 5 years revealed 307 cases of ESS. 10 had hypopituitarism, 6 had hypogonadism, 12 had hyperprolactinemia presumed due to prolactinoma, 1 each had central hypothyroidism, acromegaly and diabetes insipidus. 276 (92%) of cases had normal pituitary functional status. Concluding remarks; ESS is an uncommon but important imaging finding on brain imaging. Though most patients with ESS have normal pituitary function it may be associated with pituitary hypofunction or even hyperfunction states. Its finding in pituitary hyperfunction states like hyperprolactinemia and acromegaly make medication therapy the only viable treatment option as surgery and radiotherapy have no visible target to direct therapy.

Androgen Deprivation Followed by Acute Androgen Stimulation Selectively Sensitizes AR-Positive Prostate Cancer Cells to Ionizing Radiation.

The current standard of care for patients with locally advanced prostate cancer is a combination of androgen deprivation and radiation therapy. Radiation is typically given with androgen suppression when testosterone levels are at their nadir. Recent reports have shown that androgen stimulation of androgen-deprived prostate cancer cells leads to formation of double-strand breaks (DSB). Here, we exploit this finding and investigate the extent and timing of androgen-induced DSBs and their effect on tumor growth following androgen stimulation in combination with ionizing radiation (IR). Androgen-induced DNA damage was assessed by comet assays and γH2A.X foci formation. Effects of androgen stimulation and radiation were determined in vitro and in vivo with xenograft models. We document that androgen treatment of androgen-deprived prostate cancer cell lines resulted in a dose- and time-dependent induction of widespread DSBs. Generation of these breaks was dependent on androgen receptor and topoisomerase II beta but not on cell-cycle progression. In vitro models demonstrated a synergistic interaction between IR and androgen stimulation when IR is given at a time point corresponding with high levels of androgen-induced DSB formation. Furthermore, in vivo studies showed a significant improvement in tumor growth delay when radiation was given shortly after androgen repletion in castrated mice. These results suggest a potential cooperative effect and improved tumor growth delay with androgen-induced DSBs and radiation with implications for improving the therapeutic index of prostate cancer radiation therapy. Clin Cancer Res; 22(13); 3310-9. ©2016 AACRSee related commentary by Chua and Bristow, p. 3124.

Tissue Slice Grafts: An in Vivo Model of Human Prostate Androgen Signaling

We developed a tissue slice graft (TSG) model by implanting thin, precision-cut tissue slices derived from fresh primary prostatic adenocarcinomas under the renal capsule of immunodeficient mice. This new in vivo model not only allows analysis of approximately all of the cell types present in prostate cancer within an intact tissue microenvironment, but also provides a more accurate assessment of the effects of interventions when tissues from the same specimen with similar cell composition and histology are used as control and experimental samples. The thinness of the slices ensures that sufficient samples can be obtained for large experiments as well as permits optimal exchange of nutrients, oxygen, and drugs between the grafted tissue and the host. Both benign and cancer tissues displayed characteristic histology and expression of cell-type specific markers for up to 3 months. Moreover, androgen-regulated protein expression diminished in TSGs after androgen ablation of the host and was restored after androgen repletion. Finally, many normal secretory epithelial cells and cancer cells in TSGs remained viable 2 months after androgen ablation, consistent with similar observations in postprostatectomy specimens following neoadjuvant androgen ablation. Among these were putative Nkx3.1(+) stem cells. Our novel TSG model has the appropriate characteristics to serve as a useful tool to model all stages of disease, including normal tissue, premalignant lesions, well-differentiated cancer, and poorly differentiated cancer.

A phase II trial of rapid androgen cycling and docetaxel (Doc) in prostate cancer patients with a rising prostate-specific antigen (PSA) in the noncastrate state

5004 Introduction: Prostate cancer patients in the noncastrate state with a rapidly rising PSA are at high-risk for cancer-specific mortality. Since hormonal therapy alone is not curative, we have explored the use of rapid androgen cycling with Doc to recruit proliferating cells into successive waves of apoptosis, thereby shifting the treatment outcome for these patients from palliation to cure. Methods: Patients with noncastrate levels of testosterone (T), a rising PSA ± metastases, and = 6 months of prior hormones were eligible. Cohort 1: Six 4- week cycles of monthly leuprolide and Doc (75 mg/m2), with 7 days of topical T repletion (AndroGel 1% 5G) prior to each treatment. Cohort 2: Nine 3-week cycles of Doc (70 mg/m2), with 3 days of T repletion per cycle and 3-month depot leuprolide on day 1 of cycles 1, 5, and 9. The primary endpoint was the proportion of patients with a treatment-specific undetectable PSA at 6 and 18 months defined as: = 0.05 after surgery, = 0.5 after radiation, or = 2.0ng/ml with untreated disease. This is based on the premise that an undetectable PSA is a prerequisite to, but no guarantee of cure. Results: There were no increases in sequential PSA peaks or troughs and 100 out of 102 patients completed the planned 6 months of chemohormonal treatment. Twenty three of 62 (37%) patients in cohort 1, and 25 of 38 (66%) patients in cohort 2 achieved the primary endpoint of a treatment-specific undetectable PSA at 6 months. At 12 months, no patient in cohort 1 had maintained an undetectable PSA in the setting of a noncastrate T level; whereas, 8 of 15 (53%) patients in cohort 2 have achieved the endpoint at 12 months. Toxicities were similar to those observed with Doc and hormonal therapy administered separately. Conclusions: Rapid androgen cycling with docetaxel is feasible, and can induce successive declines in PSA peaks and troughs. The more dose-dense cohort 2 schedule of 21-day Doc administration for 9 cycles, along with reduced exposure to androgen repletion from 7 to 3 days, has resulted in a higher proportion of undetectable PSA outcomes at both 6 (66% vs. 37%) and 12 (53% vs. 0%) months. Complete PSA outcomes for cohort 2 at 12 and 18 months are still pending. Supported by Sanofi-Aventis, CA-05816, and PepsiCo. No significant financial relationships to disclose.

Rapid Androgen Cycling as Treatment for Patients with Prostate Cancer

To investigate the safety and feasibility of rapid androgen cycling for men with progressive prostate cancer. Schedule 1 included a 4-week induction of androgen depletion, followed by 4-week treatment cycles of a monthly gonadotropin-releasing hormone agonist, testosterone on days 1 to 7, and an estrogen patch on days 8 to 21. Schedule 2 included a 12-week induction of androgen depletion followed by 4-week cycles of gonadotropin-releasing hormone agonist and testosterone, but no estrogens for patients with a prostate-specific antigen (PSA) nadir <1 ng/mL after induction. The primary end point was serially declining PSA trough values over six treatment cycles. Thirty-six patients were treated; 27 were evaluable after cycling, of whom 8 of 12 (67%) and 9 of 15 (60%) on schedules 1 and 2, respectively, reached the end point. Five patients with PSA >1 ng/mL following induction did not cycle. No patient progressed radiographically or clinically during cycling. Three posttherapy PSA patterns were observed: a decline followed by a rapid increase in trough levels, a sustained decline with a plateau at a detectable nadir, and a decline to an undetectable nadir. Mean testosterone levels were castrate at the time of trough and in the normal physiologic range following androgen repletion. Major toxicities included grades 1 and 2 fatigue, hepatitis, gynecomastia, and hot flashes. Rapid hormonal cycling is feasible and well tolerated, and successive declines in PSA troughs are achievable. Although the sample size was small, the proportion of patients achieving declining PSA at the end of six cycles was comparable with that reached with continuous androgen depletion therapy.

Hormonal induction followed by rapid hormonal cycling for prostate cancer (PC): the MEN's Cycle

4609 Background: Continuous androgen deprivation (AD) is a standard therapy for systemic PC. Rapid cyclic AD and androgen repletion (AR) after a 1 month induction with castration was shown to be feasible. This trial explores a longer induction period followed by rapid cyclic AD and AR in patients (pts) with limited prior hormone exposure. Methods: Eligible pts had a rising PSA after surgery or radiation, or radiographic metastases, and ≤ 6 months of prior hormone exposure. Treatment consisted of a 3 month induction (GnRH analog monthly & bicalutamide x 1 month) followed by monthly cycles of AR (topical testosterone (T) daily x 7 days) and AD (GnRH analog monthly). A PSA of ≤1ng/ml after induction was required to proceed with cycling. PSA and T levels were monitored post ablation (troughs) and post repletion (peaks). The primary endpoint was the proportion of pts with serially declining PSA troughs after 6 cycles. Treatment failures were defined as 3 sequential increases in PSA troughs prior to 6 cycles. Results: 23 pts were enrolled (5 pts: rising PSA only; 18 pts: metastatic disease). The median baseline PSA was 63ng/ml (2.6–546). The median baseline T level was 383ng/dl (181–654). All cycling pts achieved T levels within the normal reference range during AR and castrate troughs during AD. 5 pts (22%) did not achieve a PSA of ≤1ng/ml after induction and did not cycle. 3 pts were inevaluable. Of the 15 evaluable pts who cycled, 6 pts met the primary endpoint and 3 pts are still being evaluated at < 6 cycles. 6 pts were treatment failures (all continued standard AD off study, of whom 5 pts had further PSA declines). No pt progressed radiographically. Common toxicities included grade 1 fatigue and hot flashes. Conclusion: Rapid hormonal cycling using a 3 month induction is feasible, well-tolerated, and successive declines in the PSA troughs can be achieved. Some pts did show evidence of AD resistance within 3 months by not achieving a PSA of ≤1ng/ml after induction. Based on these results, we have designed a phase II clinical trial using rapid hormonal cycling with no induction in combination with docetaxel in pts with limited prior hormone exposure. Support: CCPP, CA05826, Prostate Cancer Foundation No significant financial relationships to disclose.

Hormonal induction followed by rapid hormonal cycling for prostate cancer (PC): the MEN's Cycle

4609 Background: Continuous androgen deprivation (AD) is a standard therapy for systemic PC. Rapid cyclic AD and androgen repletion (AR) after a 1 month induction with castration was shown to be feasible. This trial explores a longer induction period followed by rapid cyclic AD and AR in patients (pts) with limited prior hormone exposure. Methods: Eligible pts had a rising PSA after surgery or radiation, or radiographic metastases, and ≤ 6 months of prior hormone exposure. Treatment consisted of a 3 month induction (GnRH analog monthly & bicalutamide x 1 month) followed by monthly cycles of AR (topical testosterone (T) daily x 7 days) and AD (GnRH analog monthly). A PSA of ≤1ng/ml after induction was required to proceed with cycling. PSA and T levels were monitored post ablation (troughs) and post repletion (peaks). The primary endpoint was the proportion of pts with serially declining PSA troughs after 6 cycles. Treatment failures were defined as 3 sequential increases in PSA troughs prior to 6 cycles. Results: 23 pts were enrolled (5 pts: rising PSA only; 18 pts: metastatic disease). The median baseline PSA was 63ng/ml (2.6–546). The median baseline T level was 383ng/dl (181–654). All cycling pts achieved T levels within the normal reference range during AR and castrate troughs during AD. 5 pts (22%) did not achieve a PSA of ≤1ng/ml after induction and did not cycle. 3 pts were inevaluable. Of the 15 evaluable pts who cycled, 6 pts met the primary endpoint and 3 pts are still being evaluated at < 6 cycles. 6 pts were treatment failures (all continued standard AD off study, of whom 5 pts had further PSA declines). No pt progressed radiographically. Common toxicities included grade 1 fatigue and hot flashes. Conclusion: Rapid hormonal cycling using a 3 month induction is feasible, well-tolerated, and successive declines in the PSA troughs can be achieved. Some pts did show evidence of AD resistance within 3 months by not achieving a PSA of ≤1ng/ml after induction. Based on these results, we have designed a phase II clinical trial using rapid hormonal cycling with no induction in combination with docetaxel in pts with limited prior hormone exposure. Support: CCPP, CA05826, Prostate Cancer Foundation No significant financial relationships to disclose.

Transient tenascin enhancement is an early event after androgen ablation in rat prostate.

Tenascin (tenascin-C), a mesenchymal glycoprotein, is expressed in many tissue remodeling processes. We evaluated tenascin expression during androgen-deprivation-related involution of the rat prostate. At set intervals following castration and subsequent testosterone repletion, prostates were removed in 30 adult rats. Each prostate was immunostained with a polyclonal antiserum against rat tenascin and keratin antibodies specifically directed against exocrine basal cells and luminal cells in the prostate glandular structure. Morphologic impressions were semiquantatively evaluated using a computer-assisted image analysis system. Rat prostates showed a transient increase in the periglandular tenascin expression directly following castration that reached a maximum at day 3. At day 6, tenascin expression was similar to control prostates. This was accompanied by a decrease of cells in the luminal cell layer. The weakest tenascin immunoreactivity was noted on day 14 after androgen withdrawal. This process was reversed by androgen repletion. This study shows that in the rat prostate tenascin expression may be androgen dependent and that during androgen deprivation-related involution tenascin expression is probably associated with tissue remodeling by stromal-epithelial interactions.

Expression of a secretory protein gene during androgen-induced cell growth.

Guinea pig seminal vesicle epithelium is an androgen-dependent tissue composed of tall columnar cells which synthesize four major secretory proteins designated SVP-1-4. Castration promptly causes the seminal vesicle epithelium cells to undergo major morphological changes. By the fifth day after castration, cell number decreases to 12% of normal, and the surviving cells are greatly involuted structurally. An injection of testosterone was sufficient to stimulate individual cell growth to the normal tall columnar configuration by 48 h without increasing cell number. Cell growth following testosterone was preceded by a 4-fold increase between 0-12 h in total cellular RNA signifying a large increase in rRNAs. To aid in the analysis of gene expression during androgen repletion, we identified a cDNA plasmid clone representing the 3'-end of the mRNA of SVP-4. The clone pAT 76 was identified by hybrid-select translation and characterization of the product of in vitro translation. The steady-state levels of SVP-4 mRNA in blots of total cellular RNA increased between 0-24 h; this appeared to be due mainly to a general nonselective increase in all or most of the abundant mRNAs. We demonstrated by in vitro translation studies that the corresponding transcript was still present during the 5th and 36th days of castration without having undergone a selective loss in abundance and during hormone repletion without undergoing a selective increase. Testosterone exerted an early and more conspicuous effect on rRNA synthesis. Whether direct or indirect this may be a key event underlying the ultimate action of testosterone, namely maintenance of cell structure.