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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Impact of Concurrent Androgen Deprivation on Fiducial Marker Migration in External-beam Radiation Therapy for Prostate Cancer

Purpose: To determine the extent of gold fiducial marker (FM) migration in patients treated for prostate cancer with concurrent androgen deprivation and external-beam radiation therapy (EBRT). Methods and Materials: Three or 4 gold FMs were implanted in 37 patients with prostate adenocarcinoma receiving androgen deprivation therapy (ADT) in conjunction with 70-78 Gy. Androgen deprivation therapy was started a median of 3.9 months before EBRT (range, 0.3-12.5 months). To establish the extent of FM migration, the distance between each FM was calculated for 5-8 treatments once per week throughout the EBRT course. For each treatment, the distance between FMs was compared with the distance from the digitally reconstructed radiographs generated from the planning CT. A total of 281 treatments were analyzed. Results: The average daily migration was 0.8 {+-} 0.3 mm, with distances ranging from 0.2 mm-2.6 mm. Two of the 281 assessed treatments (0.7%) showed migrations >2 mm. No correlation between FM migration and patient weight or time delay between ADT and start of EBRT was found. There was no correlation between the extent of FM migration and prostate volume. Conclusion: This is the largest report of implanted FM migration in patients receiving concomitant ADT. Only 0.7% of the 281 treatments studied had significant marker migrations (>2 mm) throughout the course of EBRT. Consequently, the use of implanted FMs in these patients enables accurate monitoring of prostate gland position during treatment.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Sunitinib Plus Androgen Deprivation and Radiation Therapy for Patients With Localized High-Risk Prostate Cancer: Results From a Multi-institutional Phase 1 Study

Purpose: To evaluate the feasibility of administering sunitinib in combination with androgen deprivation therapy and external-beam intensity modulated radiation therapy (XRT) in patients with localized high-risk prostate cancer. Methods and Materials: Seventeen men with localized adenocarcinoma of the prostate with cT2c-cT4 or Gleason 8-10 or prostate-specific antigen >20 ng/mL received initial androgen deprivation (leuprolide 22.5 mg every 12 weeks plus oral bicalutamide 50 mg daily) for 4-8 weeks before oral sunitinib 12.5, 25, or 37.5 mg daily for 4 weeks as lead-in, then concurrently with and 4 weeks after XRT (75.6 Gy in 42 fractions to prostate and seminal vesicles). A 3+3 sequential dose-escalation design was used to assess the frequency of dose-limiting toxicity (DLT) and establish a maximal tolerated dose of sunitinib. Results: Sunitinib at 12.5- and 25-mg dose levels was well tolerated. The first 4 patients enrolled at 37.5 mg experienced a DLT during lead-in, and a drug interaction between sunitinib and bicalutamide was suspected. The protocol was revised and concurrent bicalutamide omitted. Of the next 3 patients enrolled at 37.5 mg, 2 of 3 receiving concurrent therapy experienced DLTs during radiation: grade 3 diarrhea and grade 3 proctitis, respectively. Only 1 of 7 patients completed sunitinib at 37.5 mg daily, whereas 3 of 3 patients (25 mg as starting dose) and 3 of 4 patients (25 mg as reduced dose) completed therapy. Conclusions: The feasibility of combined vascular endothelial growth factor receptor (VEGFR)/platelet-derived growth factor receptor (PDGFR) inhibitor therapy, androgen deprivation, and radiation therapy for prostate cancer was established. Using a daily dosing regimen with lead-in, concurrent, and post-XRT therapy, the recommended phase 2 dose of sunitinib is 25 mg daily.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

17β-trenbolone, an anabolic–androgenic steroid as well as an environmental hormone, contributes to neurodegeneration

Both genetic and environmental factors contribute to neurodegenerative disorders. In a large number of neurodegenerative diseases (for example, Alzheimer's disease (AD)), patients do not carry the mutant genes. Other risk factors, for example the environmental factors, should be evaluated. 17β-trenbolone is a kind of environmental hormone as well as an anabolic–androgenic steroid. 17β-trenbolone is used as a growth promoter for livestock in the USA. Also, a large portion of recreational exercisers inject 17β-trenbolone in large doses and for very long time to increase muscle and strength. 17β-trenbolone is stable in the environment after being excreted. In the present study, 17β-trenbolone was administered to adult and pregnant rats and the primary hippocampal neurons. 17β-trenbolone's distribution and its effects on serum hormone levels and Aβ42 accumulation in vivo and its effects on AD related parameters in vitro were assessed. 17β-trenbolone accumulated in adult rat brain, especially in the hippocampus, and in the fetus brain. It altered Aβ42 accumulation. 17β-trenbolone induced apoptosis of primary hippocampal neurons in vitro and resisted neuroprotective function of testosterone. Presenilin-1 protein expression was down-regulated while β-amyloid peptide 42 (Aβ42) production and caspase-3 activities were increased. Both androgen and estrogen receptors mediated the processes. 17β-trenbolone played critical roles in neurodegeneration. Exercisers who inject large doses of trenbolone and common people who are exposed to 17β-trenbolone by various ways are all influenced chronically and continually. Identification of such environmental risk factors will help us take early prevention measure to slow down the onset of neurodegenerative disorders. - Highlights: • The widely used anabolic–androgenic steroid 17β-trenbolone has neurotoxicity. • 17β-trenbolone crosses the blood brain barrier and placental barrier. • Rat has high level of 17β-trenbolone in hippocampus after intramuscular injection. • 17β-trenbolone induces apoptosis of primary hippocampal neurons. • 17β-trenbolone affects Alzheimer's disease-related proteins Aβ42 and presenilin-1.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

High Accuracy Indicators of Androgen Suppression Therapy Failure for Prostate Cancer—A Modeling Study

Prostate cancer is a serious public health concern in the United States. The primary obstacle to effective long-term management for prostate cancer patients is the eventual development of treatment resistance. Due to the uniquely chaotic nature of the neoplastic genome, it is difficult to determine the evolution of tumor composition over the course of treatment. Hence, a drug is often applied continuously past the point of effectiveness, thereby losing any potential treatment combination with that drug permanently to resistance. If a clinician is aware of the timing of resistance to a particular drug, then they may have a crucial opportunity to adjust the treatment to retain the drug’s usefulness in a potential treatment combination or strategy. In this study, we investigate new methods of predicting treatment failure due to treatment resistance using a novel mechanistic model built on an evolutionary interpretation of Droop cell quota theory. We analyze our proposed methods using patient PSA and androgen data from a clinical trial of intermittent treatment with androgen deprivation therapy. Our results produce two indicators of treatment failure. The first indicator, proposed from the evolutionary nature of the cancer population, is calculated using our mathematical model with a predictive accuracy of 87.3% (sensitivity: 96.1%, specificity: 65%). The second indicator, conjectured from the implication of the first indicator, is calculated directly from serum androgen and PSA data with a predictive accuracy of 88.7% (sensitivity: 90.2%, specificity: 85%). Our results demonstrate the potential and feasibility of using an evolutionary tumor dynamics model in combination with the appropriate data to aid in the adaptive management of prostate cancer.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1983

Androgens enhance in vivo 2-deoxyglucose uptake by rat striated muscle

It is shown that testosterone propionate (TP) causes a striking increase in the in vivo uptake of 2-deoxyglucose (2-DG) by the levator ani muscle of immature male rats, which was found to be uniformly distributed over the entire muscle. After a single subcutaneous injection of TP, no enhancement of 2-DG was observed before 3.5 hr, at which time uptake was increased 2-fold; maximum enhancement (4-fold) was attained at 12 hr. At 72 hr, 2-DG uptake remained elevated at twice the control value. It was determined that the effect of TP probably is mediated by specific androgen receptors. In addition, it was found that the effect of TP was blocked by the simultaneous administration of an androgen antagonist, cyproterone acetate. TP also was found to enhance the uptake of 2-DG in the bulbocavernosus (253 percent over control) and extensor digitorum longus muscles (150 percent over control), but not in the biceps brachii or soleus. It is suggested that the increased uptake of glucose may be an important early step in the anabolic response of muscle to androgens.

Max, S. R.↗
DOE OSTI2018

TSG101 interacts with the androgen receptor and attenuates its expression through the endosome/lysosome pathway

Highlights: • TSG101interacts with AR and recruits AR to its associated late endosome structure. • TSG101 overexpression reduces AR protein level and its transactivation activity. • The downregulation of AR is mediated by TSG101 through lysosomal degradation. The androgen receptor (AR) signaling pathway plays a vital role in the normal development and function of the male reproductive organs. Dysregulation of the androgen-AR signaling pathway has been linked to prostate cancer. Here, we demonstrate that tumor susceptibility gene 101 (TSG101) regulates AR expression level via the endosome/lysosome degradation pathway. In LNCaP cells, TSG101 overexpression recruits the AR to TSG101-containing cytoplasmic vesicles resulting in reduced AR protein level and AR transactivation activity downregulation. Immunofluorescence microscopy demonstrated that TSG101-decorated cytoplasmic vesicles are associated with late endosomes/lysosomes and the AR could be found within the Lamp2 positive TSG101 vesicles upon lysosomal protease inhibitor treatment. Furthermore, chloroquine or bafilomycin A1 treatment was able to restore TSG101-mediated AR expression reduction. Based on these data, we conclude that the interaction of the AR and TSG101 leads to AR recruitment to TSG101-containing cytoplasmic vesicles and induces AR-attenuated expression through the late endosome/lysosome degradation pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

BAF53A regulates androgen receptor-mediated gene expression and proliferation in LNCaP cells

The actin-like protein of the SWI/SNF complex, BAF53A, regulates gene expression by the gene-specific chromatin remodeling of target genes. However, the function of BAF53A in the androgen receptor pathway in prostate cancer cells remains unclear. Here, we demonstrated that BAF53A positively regulates the expression of endogenous AR target genes (e.g. PSA, TMPRSS2, FKBP5, and KLK2) in LNCaP cells. It functions as a coactivator in AR-mediated transcription by interacting with other nuclear receptor coactivators, such as p300 and FLII, and is associated with AR in the presence of dihydrotestosterone (DHT). The DHT-induced recruitment of BAF53A to the proximal and distal androgen response elements (AREs) of the PSA gene in the presence of BRG1 (but not BRM) was inhibited by an AR antagonist, suggesting the coactivator function of BAF53A in the SWI/SNF complex. Depletion of BAF53A in LNCaP cells resulted in a significant decrease in growth rate. Furthermore, the expression of BAF53A in prostate cancer tissue was significantly elevated, compared to that in normal prostate tissue, and correlated with the expression of AR, and BRG1, but not BRM. Therefore, our results suggested that BAF53A plays an important role in the expression of AR target genes in prostate cancer, and can be used clinically for the treatment of prostate cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

PSA Response to Neoadjuvant Androgen Deprivation Therapy Is a Strong Independent Predictor of Survival in High-Risk Prostate Cancer in the Dose-Escalated Radiation Therapy Era

Purpose: The aim of the study was to evaluate the prognostic value of prostate-specific antigen (PSA) response to neoadjuvant androgen deprivation therapy (ADT) prior to dose-escalated radiation therapy (RT) and long-term ADT in high-risk prostate cancer. Methods and Materials: We reviewed the charts of all patients diagnosed with high-risk prostate cancer and treated with a combination of long-term ADT (median, 24 months) and dose-escalated (median, 75.6 Gy) RT between 1990 and 2007. The associations among patient, tumor, and treatment characteristics with biochemical response to neoadjuvant ADT and their effects on failure-free survival (FFS), time to distant metastasis (TDM), prostate cancer-specific mortality (PCSM) and overall survival (OS) were examined. Results: A total of 196 patients met criteria for inclusion. Median follow-up time for patients alive at last contact was 7.0 years (range, 0.5-18.1 years). Multivariate analysis identified the pre-RT PSA concentration (<0.5 vs {>=}0.5 ng/mL) as a significant independent predictor of FFS (P=.021), TDM (P=.009), PCSM (P=.039), and OS (P=.037). On multivariate analysis, pretreatment PSA (iPSA) and African-American race were significantly associated with failure to achieve a pre-RT PSA of <0.5 ng/mL. Conclusions: For high-risk prostate cancer patients treated with long-term ADT and dose-escalated RT, a pre-RT PSA level {>=}0.5 ng/mL after neoadjuvant ADT predicts for worse survival measures. Both elevated iPSA and African-American race are associated with increased risk of having a pre-RT PSA level {>=}0.5 ng/mL. These patients should be considered for clinical trials that test newer, more potent androgen-depleting therapies such as abiraterone and MDV3100 in combination with radiation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Mixture effects at very low doses with combinations of anti-androgenic pesticides, antioxidants, industrial pollutant and chemicals used in personal care products

Many xenobiotics have been identified as in vitro androgen receptor (AR) antagonists, but information about their ability to produce combined effects at low concentrations is missing. Such data can reveal whether joint effects at the receptor are induced at low levels and may support the prioritisation of in vivo evaluations and provide orientations for the grouping of anti-androgens in cumulative risk assessment. Combinations of 30 AR antagonists from a wide range of sources and exposure routes (pesticides, antioxidants, parabens, UV-filters, synthetic musks, bisphenol-A, benzo(a)pyrene, perfluorooctane sulfonate and pentabromodiphenyl ether) were tested using a reporter gene assay (MDA-kb2). Chemicals were combined at three mixture ratios, equivalent to single components' effect concentrations that inhibit the action of dihydrotesterone by 1%, 10% or 20%. Concentration addition (CA) and independent action were used to calculate additivity expectations. We observed complete suppression of dihydrotestosterone effects when chemicals were combined at individual concentrations eliciting 1%, 10% or 20% AR antagonistic effect. Due to the large number of mixture components, the combined AR antagonistic effects occurred at very low concentrations of individual mixture components. CA slightly underestimated the combined effects at all mixture ratios. In conclusion, large numbers of AR antagonists from a wide variety of sources and exposure routes have the ability of acting together at the receptor to produce joint effects at very low concentrations. Significant mixture effects are observed when chemicals are combined at concentrations that individually do not induce observable AR antagonistic effects. Cumulative risk assessment for AR antagonists should apply grouping criteria based on effects where data are available, rather than on criteria of chemical similarity. - Highlights: • Mixtures of AR antagonists at low individual concentrations cause complete inhibition. • Concentration addition was an appropriate prediction model for observed effects. • Risk assessment for AR antagonists should use grouping criteria based on effects.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

The value of integrating pre-clinical data to predict nausea and vomiting risk in humans as illustrated by AZD3514, a novel androgen receptor modulator

Nausea and vomiting are components of a complex mechanism that signals food avoidance and protection of the body against the absorption of ingested toxins. This response can also be triggered by pharmaceuticals. Predicting clinical nausea and vomiting liability for pharmaceutical agents based on pre-clinical data can be problematic as no single animal model is a universal predictor. Moreover, efforts to improve models are hampered by the lack of translational animal and human data in the public domain. AZD3514 is a novel, orally-administered compound that inhibits androgen receptor signaling and down-regulates androgen receptor expression. Here we have explored the utility of integrating data from several pre-clinical models to predict nausea and vomiting in the clinic. Single and repeat doses of AZD3514 resulted in emesis, salivation and gastrointestinal disturbances in the dog, and inhibited gastric emptying in rats after a single dose. AZD3514, at clinically relevant exposures, induced dose-responsive “pica” behaviour in rats after single and multiple daily doses, and induced retching and vomiting behaviour in ferrets after a single dose. We compare these data with the clinical manifestation of nausea and vomiting encountered in patients with castration-resistant prostate cancer receiving AZD3514. Our data reveal a striking relationship between the pre-clinical observations described and the experience of nausea and vomiting in the clinic. In conclusion, the emetic nature of AZD3514 was predicted across a range of pre-clinical models, and the approach presented provides a valuable framework for predicition of clinical nausea and vomiting. - Highlights: • Integrated pre-clinical data can be used to predict clinical nausea and vomiting. • Data integrated from standard toxicology studies is sufficient to make a prediction. • The use of the nausea algorithm developed by Parkinson (2012) aids the prediction. • Additional pre-clinical studies can be used to confirm and quantify the risk.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Combination of Radiation Therapy and Short-Term Androgen Blockade With Abiraterone Acetate Plus Prednisone for Men With High- and Intermediate-Risk Localized Prostate Cancer

Long-term androgen-deprivation therapy (ADT) is the standard of care in combination with radiation therapy (RT) in high-risk prostate cancer (PC), despite substantial toxicity from the resulting hypogonadism. We hypothesized that a combination of more potent but shorter-term androgen inhibition in men with intermediate- or high-risk localized PC would synergize with definitive RT to provide short-term testosterone recovery and improve disease control.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
NASA NTRS1984

Androgen-estrogen synergy in rat levator ani muscle Glucose-6-phosphate dehydrogenase

The effects of castration and hormone administration on the activity of glucose-6-phosphate dehydrogenase in the rat levator ani muscle were studied. Castration caused a decrease in enzyme activity and in wet weight of the levator ani muscle. Chronic administration of testosterone propionate increased glucose-6-phosphate dehydrogenase activity in the levator ani muscle of castrated rats; the magnitude of the recovery of enzyme activity was related to the length of time of exposure to testosterone propionate after castration as well as to the length of time the animals were castrated. The longer the period of castration before exposure to testosterone propionate, the greater the effect. This result may be related to previously reported castration-mediated increases in androgen receptor binding in muscle. Dihydrotestosterone was less effective than testosterone propionate in enhancing glucose-6-phosphate dehydrogenase activity in the levator ani muscle from castrated rats; estradiol-17-beta alone was ineffective. Combined treatment with estradiol-17-beta and dihydrotestosterone, however, was as effective as testosterone alone. Thus, androgens and estrogens may exert synergistic effects on levator ani muscle.

Max, S. R.↗
DOE OSTI2019

Design, synthesis, and biological evaluation of 2-(5-methyl-1H-pyrazol-1-yl) acetamide derivatives as androgen receptor antagonists

Androgen receptor (AR) signaling is often activated in prostate cancer (PCa) cells, and blockage of this signaling by AR antagonists is an important strategy in PCa therapy. In this study, we designed and synthesized a series of 2-(5-methyl-1H-pyrazol-1-yl) acetamide derivatives, and evaluated their biological activities. AR luciferase reporter assay revealed compound 6f (59.7%) as a potent AR antagonist. Some compounds in this series showed higher anti-proliferative activity against LNCaP cells than Bicalutamide (IC{sub 50} = 35.0 μM), especially 6g with IC{sub 50} value of 13.6 μM.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Histone H4 Lys 20 methyltransferase SET8 promotes androgen receptor-mediated transcription activation in prostate cancer

Highlights: • Dihydrotestosterone stimulates H4K20me1 enrichment at the PSA promoter. • SET8 promotes AR-mediated transcription activation. • SET8 interacts with AR and promotes cell proliferation. - Abstract: Histone methylation status in different lysine residues has an important role in transcription regulation. The effect of H4K20 monomethylation (H4K20me1) on androgen receptor (AR)-mediated gene transcription remains unclear. Here we show that AR agonist stimulates the enrichment of H4K20me1 and SET8 at the promoter of AR target gene PSA in an AR dependent manner. Furthermore, SET8 is crucial for the transcription activation of PSA. Co-immunoprecipitation analyses demonstrate that SET8 interacts with AR. Therefore, we conclude that SET8 is involved in AR-mediated transcription activation, possibly through its interaction with AR and H4K20me1 modification.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Androgen-responsive circular RNA circSMARCA5 is up-regulated and promotes cell proliferation in prostate cancer

Prostate cancer (PCa) is one of the most commonly diagnosed cancers in males worldwide. Circular RNA (circRNA) is a unique class of RNA transcribed by RNA polymerase II characterized by jointing 3′ and 5′ ends together via exon or intron circularization. However, the molecular functions of circRNAs in prostate cancer have rarely been explored. In present study, we found circ-SMARCA5 was up-regulated in prostate cancer samples compared to match normal tissues. We also observed circ-SMARCA5 expression was significantly induced after DHT treatment. Functional experiments showed circ-SMARCA5 acted as an oncogene in prostate cancer by promoting cell cycle and inhibiting cell apoptosis. We thought this study provided useful information for exploring circRNAs as potential therapeutic and prognostic targets for prostate cancer. - Highlights: • To our knowledge, this is the first study to explore the molecular functions of circRNA in prostate cancer. • Our study showed that circ-SMARCA5 promoted cell proliferation and inhibited cell apoptosis in prostate cancer. • circ-SMARCA5 was for the first time reported as an androgen-responsive circRNA. • circ-SMARCA5 was for the first time reported to be up-regulated in prostate cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Implementation of High-Dose-Rate Brachytherapy and Androgen Deprivation in Patients With Prostate Cancer

Purpose: To evaluate outcome (overall survival [OS], the actuarial 5-year cancer-specific survival [CSS], disease-free survival [DFS], biochemical failure-free survival [BFS]), complications and morbidity in patients treated with high-dose-rate brachytherapy (HDR-BT) boost and hormonal treatment with curative aims. Methods: Between 2004 and 2009, 275 prospectively followed pN0/N0M0 patients were included: 19 patients (7%) with T2, Gleason score 7 and prostate-specific antigen (PSA) <10 and 256 patients (93%) with T3 or Gleason score 8-10 or PSA >20 received multimodal treatment with conformal four-field radiotherapy (prostate/vesiculae 2 Gy Multiplication-Sign 25) combined with HDR-BT (iridium 192; prostate 10 Gy Multiplication-Sign 2) with long-term androgen deprivation therapy (ADT). Results: After a median observation time of 44.2 months (range, 10.4-90.5 months) 12 patients had relapsed clinically and/or biochemically and 10 patients were dead, of which 2 patients died from prostate cancer. Five-year estimates of BFS, CSS, DFS, and OS rates were 98.5%, 99.3%, 95.6%, and 96.3%, respectively. None of the patients with either Gleason score <8 or with intermediate risk profile had relapsed. The number of HDR-BT treatments was not related to outcome. Despite of age (median, 65.7 years; range, 45.7-77 years) and considerable pretreatment comorbidity in 39 of 275 patients, Genitourinary treatment-related morbidity was moderate with long-lasting Radiation Therapy Oncology Group Grade 2 voiding problems in 26 patients (9.5%) and occasionally mucous discharge in 20 patients (7%), none with Grade >2 for gastrointestinal at follow-up. Complications during implantations were related to pubic arch interference (4 patients) and lithotomy time, causing 2 patients to develop compartment syndrome. Conclusion: Despite still preliminary observations, our 5-year outcome estimates favor the implementation of high-dose-rate brachytherapy in high-risk patients combined with conformal external radiotherapy and long-term ADT. High-quality implants can be achieved by a trained specialized team at a high-turnover center using transrectal ultrasound-based treatment plans with acceptable morbidity and complication rates.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

High-Dose Adjuvant Radiotherapy After Radical Prostatectomy With or Without Androgen Deprivation Therapy

Purpose: To retrospectively evaluate the outcome and toxicity in patients receiving high-dose (>69 Gy) adjuvant radiotherapy (HD-ART) and the impact of androgen deprivation therapy (ADT). Methods and Materials: Between 1999 and 2008, 225 node-negative patients were referred for HD-ART with or without ADT to two large academic institutions. Indications for HD-ART were extracapsular extension, seminal vesicle invasion (SVI), and/or positive surgical margins at radical prostatectomy (RP). A dose of at least 69.1 Gy was prescribed to the prostate bed and seminal vesicle bed. The ADT consisted of a luteinizing hormone-releasing hormone analog. The duration and indication of ADT was left at the discretion of the treating physician. The effect of HD-ART and ADT on biochemical (bRFS) and clinical (cRFS) relapse-free survival was examined through univariate and multivariate analysis, with correction for known patient- and treatment-related variables. Interaction terms were introduced to evaluate effect modification. Results: After a median follow-up time of 5 years, the 7-year bRFS and cRFS were 84% and 88%, respectively. On multivariate analysis, the addition of ADT was independently associated with an improved bRFS (hazard ratio [HR] 0.4, p = 0.02) and cRFS (HR 0.2, p = 0.008). Higher Gleason scores and SVI were associated with decreased bRFS and cRFS. A lymphadenectomy at the time of RP independently improved cRFS (HR 0.09, p = 0.009). The 7-year probability of late Grade 2-3 toxicity was 29% and 5% for genitourinary (GU) and gastrointestinal (GI) symptoms, respectively. The absolute incidence of Grade 3 toxicity was <1% and 10% for GI and GU symptoms, respectively. The study is limited by its retrospective design and the lack of a standardized use of ADT. Conclusions: This retrospective study shows significantly improved bRFS and cRFS rates with the addition of ADT to HD-ART, with low Grade 3 gastrointestinal toxicity and 10% Grade 3 genitourinary toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

High-Dose Radiotherapy With or Without Androgen Deprivation Therapy for Intermediate-Risk Prostate Cancer: Cancer Control and Toxicity Outcomes

Purpose: To evaluate the impact of short-course androgen deprivation therapy (ADT) on cancer control outcomes and toxicity in intermediate-risk prostate cancer treated with dose-escalated external beam radiotherapy (high-dose radiotherapy [HDRT]). Methods and Materials: Demographic, disease, and treatment characteristics of prostate cancer patients at 2 institution consortiums were charted. Of 296 men with intermediate-risk prostate cancer (defined as {>=}T2b, prostate-specific antigen level >10 ng/mL, or Gleason score [GS] of 7, with none of the following: {>=}T3, prostate-specific antigen level >20 ng/mL, GS {>=}8, or positive nodes) treated with HDRT to a dose of 72 Gy or greater, 123 received short-course ADT and 173 did not. Univariate and multivariate analyses on biochemical failure-free survival (BFFS) (including subset analysis by disease factors) and on overall survival (OS) were performed, as were comparisons of gastrointestinal (GI) and genitourinary (GU) toxicity rates. Results: For the whole group, the median dose was 75.6 Gy; the minimum follow-up was 2 years, and the median follow-up was 47.4 months. For ADT vs. no ADT, the 5-year BFFS rate was 86% vs. 79% (p = 0.138) and the 5-year OS rate was 87% vs. 80% (p = 0.159). On multivariate analysis, percent positive cores (PPC) (p = 0.002) and GS (p = 0.008) were significantly associated with BFFS, with ADT showing a trend (p = 0.055). The impact of ADT was highest in the subsets with PPC greater than 50% (p = 0.019), GS 4+3 (p = 0.078), and number of risk factors greater than 1 (p = 0.022). Only intensity-modulated radiotherapy use (p = 0.012) and GS (p = 0.023) reached significance for OS, and there were no significant differences in GU or GI toxicity. Conclusions: Although the use of ADT with HDRT did not influence BFFS, our study suggests a benefit in patients with PPC greater than 50%, GS 4+3, or multiple risk factors. No OS benefit was shown, and ADT was not associated with additional radiotherapy-related GI or GU toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗