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At least 1,657 records · Page 92
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Intensity-Modulated Radiotherapy Reduces Gastrointestinal Toxicity in Patients Treated With Androgen Deprivation Therapy for Prostate Cancer

Purpose: Androgen deprivation therapy (AD) has been shown to increase late Grade 2 or greater rectal toxicity when used concurrently with three-dimensional conformal radiotherapy (3D-CRT). Intensity-modulated radiotherapy (IMRT) has the potential to reduce toxicity by limiting the radiation dose received by the bowel and bladder. The present study compared the genitourinary and gastrointestinal (GI) toxicity in men treated with 3D-CRT+AD vs. IMRT+AD. Methods and Materials: Between July 1992 and July 2004, 293 men underwent 3D-CRT (n = 170) or IMRT (n = 123) with concurrent AD (<6 months, n = 123; {>=}6 months, n = 170). The median radiation dose was 76 Gy for 3D-CRT (International Commission on Radiation Units and Measurements) and 76 Gy for IMRT (95% to the planning target volume). Toxicity was assessed by a patient symptom questionnaire that was completed at each visit and recorded using a Fox Chase Modified Late Effects Normal Tissue Task radiation morbidity scale. Results: The mean follow-up was 86 months (standard deviation, 29.3) for the 3D-CRT group and 40 months (standard deviation, 9.7) for the IMRT group. Acute GI toxicity (odds ratio, 4; 95% confidence interval, 1.6-11.7; p = .005) was significantly greater with 3D-CRT than with IMRT and was independent of the AD duration (i.e., <6 vs. {>=}6 months). The interval to the development of late GI toxicity was significantly longer in the IMRT group. The 5-year Kaplan-Meier estimate for Grade 2 or greater GI toxicity was 20% for 3D-CRT and 8% for IMRT (p = .01). On multivariate analysis, Grade 2 or greater late GI toxicity (hazard ratio, 2.1; 95% confidence interval, 1.1-4.3; p = .04) was more prevalent in the 3D-CRT patients. Conclusion: Compared with 3D-CRT, IMRT significantly decreased the acute and late GI toxicity in patients treated with AD.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Timing of Radiotherapy and Outcome in Patients Receiving Adjuvant Endocrine Therapy

Purpose: To evaluate the association between the interval from breast-conserving surgery (BCS) to radiotherapy (RT) and the clinical outcome among patients treated with adjuvant endocrine therapy. Patients and Methods: Patient information was obtained from three International Breast Cancer Study Group trials. The analysis was restricted to 964 patients treated with BCS and adjuvant endocrine therapy. The patients were divided into two groups according to the median number of days between BCS and RT and into four groups according to the quartile of time between BCS and RT. The endpoints were the interval to local recurrence, disease-free survival, and overall survival. Proportional hazards regression analysis was used to perform comparisons after adjustment for baseline factors. Results: The median interval between BCS and RT was 77 days. RT timing was significantly associated with age, menopausal status, and estrogen receptor status. After adjustment for these factors, no significant effect of a RT delay {<=}20 weeks was found. The adjusted hazard ratio for RT within 77 days vs. after 77 days was 0.94 (95% confidence interval [CI], 0.47-1.87) for the interval to local recurrence, 1.05 (95% CI, 0.82-1.34) for disease-free survival, and 1.07 (95% CI, 0.77-1.49) for overall survival. For the interval to local recurrence the adjusted hazard ratio for {<=}48, 49-77, and 78-112 days was 0.90 (95% CI, 0.34-2.37), 0.86 (95% CI, 0.33-2.25), and 0.89 (95% CI, 0.33-2.41), respectively, relative to {>=}113 days. Conclusion: A RT delay of {<=}20 weeks was significantly associated with baseline factors such as age, menopausal status, and estrogen-receptor status. After adjustment for these factors, the timing of RT was not significantly associated with the interval to local recurrence, disease-free survival, or overall survival.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Population-Based Study of Cardiovascular Mortality Among Patients With Prostate Cancer Treated With Radical External Beam Radiation Therapy With and Without Adjuvant Androgen Deprivation Therapy at the British Columbia Cancer Agency

Purpose: There are conflicting studies of the impact of androgen deprivation therapy (ADT) on cardiovascular (CV) mortality among prostate cancer patients receiving curative intent external beam radiation therapy (EBRT). We assessed the impact of ADT on CV mortality in patients treated in British Columbia. Methods and Materials: Provincial pharmacy and radiotherapy databases were linked to the provincial cancer registry, and defined a cohort of patients treated with curative intent EBRT between 1998 and 2005. We determined the duration of ADT and the cumulative incidence of CV death. We compared death from CV disease with and without ADT, and by duration of ADT using competing risk analysis and Fine and Gray multivariant analysis. A total of 600 randomly selected patients were reviewed to determine baseline CV disease, CV risk factors, and Charlson Index. Results: Of 5,948 prostate cancer patients treated with radical intent EBRT, of whom 1,933 were treated without ADT, 674 received ADT for {<=}6 months and 3,341 received > 6 months of ADT. The cumulative CV mortality at 7 years was 2.6% (95% confidence interval [CI] 1.9-3.5%), 2.1% (95% CI = 1.2-3.5%), and 1.4 (95% CI = 1.0-2.0%) for patients with no ADT, {<=}6 months of ADT, and >6 months of ADT, respectively (Gray's p = 0.002). Baseline CV disease and risk factors were more prevalent in the no-ADT group compared with the >6-month ADT group. Conclusions: This study demonstrated a lower CV mortality rate among patients treated with longer durations of ADT than those treated without ADT. These differences likely relate to selection of patients for ADT rather than effect of ADT itself.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Insulin-Like Growth Factor-1 Preserves Salivary Gland Function After Fractionated Radiation

Purpose: Radiotherapy for head-and-neck cancer consists of fractionated radiation treatments that cause significant damage to salivary glands leading to chronic salivary gland dysfunction with only limited prevention and treatment options currently available. This study examines the feasibility of IGF-1 in preserving salivary gland function following a fractionated radiation treatment regimen in a pre-clinical model. Methods and Materials: Mice were exposed to fractionated radiation, and salivary gland function and histological analyses of structure, apoptosis, and proliferation were evaluated. Results: In this study, we report that treatment with fractionated doses of radiation results in a significant level of apoptotic cells in FVB mice after each fraction, which is significantly decreased in transgenic mice expressing a constitutively active mutant of Akt1 (myr-Akt1). Salivary gland function is significantly reduced in FVB mice exposed to fractionated radiation; however, myr-Akt1 transgenic mice maintain salivary function under the same treatment conditions. Injection into FVB mice of recombinant insulin-like growth factor-1 (IGF-1), which activates endogenous Akt, suppressed acute apoptosis and preserved salivary gland function after fractionated doses of radiation 30 to 90 days after treatment. FVB mice exposed to fractionated radiation had significantly lower levels of proliferating cell nuclear antigen-positive salivary acinar cells 90 days after treatment, which correlated with a chronic loss of function. In contrast, FVB mice injected with IGF-1 before each radiation treatment exhibited acinar cell proliferation rates similar to those of untreated controls. Conclusion: These studies suggest that activation of IGF-1-mediated pathways before head-and-neck radiation could modulate radiation-induced salivary gland dysfunction and maintain glandular homeostasis.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

70 Gy Versus 80 Gy in Localized Prostate Cancer: 5-Year Results of GETUG 06 Randomized Trial;Prostate cancer; Dose escalation; Conformal radiotherapy; Randomized trial

Purpose: To perform a randomized trial comparing 70 and 80 Gy radiotherapy for prostate cancer. Patients and Methods: A total of 306 patients with localized prostate cancer were randomized. No androgen deprivation was allowed. The primary endpoint was biochemical relapse according to the modified 1997-American Society for Therapeutic Radiology and Oncology and Phoenix definitions. Toxicity was graded using the Radiation Therapy Oncology Group 1991 criteria and the late effects on normal tissues-subjective, objective, management, analytic scales (LENT-SOMA) scales. The patients' quality of life was scored using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire 30-item cancer-specific and 25-item prostate-specific modules. Results: The median follow-up was 61 months. According to the 1997-American Society for Therapeutic Radiology and Oncology definition, the 5-year biochemical relapse rate was 39% and 28% in the 70- and 80-Gy arms, respectively (p = .036). Using the Phoenix definition, the 5-year biochemical relapse rate was 32% and 23.5%, respectively (p = .09). The subgroup analysis showed a better biochemical outcome for the higher dose group with an initial prostate-specific antigen level >15 ng/mL. At the last follow-up date, 26 patients had died, 10 of their disease and none of toxicity, with no differences between the two arms. According to the Radiation Therapy Oncology Group scale, the Grade 2 or greater rectal toxicity rate was 14% and 19.5% for the 70- and 80-Gy arms (p = .22), respectively. The Grade 2 or greater urinary toxicity was 10% at 70 Gy and 17.5% at 80 Gy (p = .046). Similar results were observed using the LENT-SOMA scale. Bladder toxicity was more frequent at 80 Gy than at 70 Gy (p = .039). The quality-of-life questionnaire results before and 5 years after treatment were available for 103 patients with no differences found between the 70- and 80-Gy arms. Conclusion: High-dose radiotherapy provided a better 5-year biochemical outcome with slightly greater toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Lack of Benefit for the Addition of Androgen Deprivation Therapy to Dose-Escalated Radiotherapy in the Treatment of Intermediate- and High-Risk Prostate Cancer

Purpose: Assessment of androgen deprivation therapy (ADT) benefits for prostate cancer treated with dose-escalated radiotherapy (RT). Methods and Materials: From 1991 to 2004, 1,044 patients with intermediate- (n = 782) or high-risk (n = 262) prostate cancer were treated with dose-escalated RT at William Beaumont Hospital. Patients received external-beam RT (EBRT) alone, brachytherapy (high or low dose rate), or high dose rate brachytherapy plus pelvic EBRT. Intermediate-risk patients had Gleason score 7, prostate-specific antigen (PSA) 10.0-19.9 ng/mL, or Stage T2b-T2c. High-risk patients had Gleason score 8-10, PSA {>=}20, or Stage T3. Patients were additionally divided specifically by Gleason score, presence of palpable disease, and PSA level to further define subgroups benefitting from ADT. Results: Median follow-up was 5 years; 420 patients received ADT + dose-escalated RT, and 624 received dose-escalated RT alone. For all patients, no advantages in any clinical endpoints at 8 years were associated with ADT administration. No differences in any endpoints were associated with ADT administration based on intermediate- vs. high-risk group or RT modality when analyzed separately. Patients with palpable disease plus Gleason {>=}8 demonstrated improved clinical failure rates and a trend toward improved survival with ADT. Intermediate-risk patients treated with brachytherapy alone had improved biochemical control when ADT was given. Conclusion: Benefits of ADT in the setting of dose-escalated RT remain poorly defined. This question must continue to be addressed in prospective study.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

A Matched Control Analysis of Adjuvant and Salvage High-Dose Postoperative Intensity-Modulated Radiotherapy for Prostate Cancer

Purpose: It is unclear whether immediate adjuvant radiotherapy for high-risk disease at prostatectomy (capsule perforation, seminal vesicle invasion, and/or positive surgical margins) is equivalent to delayed salvage radiotherapy at biochemical recurrence. We performed a matched case analysis comparing high-dose adjuvant intensity modulated radiotherapy (A-IMRT) with salvage IMRT (S-IMRT). Methods and Materials: One hundred forty-four patients with high-risk disease at prostatectomy were referred for A-IMRT, and 134 patients with high-risk disease were referred at biochemical recurrence (rising prostate-specific antigen [PSA], following prostatectomy, above 0.2 ng/ml) for S-IMRT. Patients were matched in a 1:1 ratio according to preoperative PSA level, Gleason score, and pT stage. Median doses of 74 Gy and 76 Gy were prescribed for A-IMRT and S-IMRT, respectively. We report biochemical relapse free survival (bRFS) rates using the Kaplan-Meier method. Univariate and multivariate analyses were used to examine tumour- and treatment-related factors. Results: A total of 178 patients were matched (89:89). From the end of radiotherapy, the median follow-up was 36 months for both groups. The 3-year bRFS rate for the A-IMRT group was 90% compared to 65% for the S-IMRT group (p < 0.05). On multivariate analysis, S-IMRT, Gleason grades of {>=}4+3, perineural invasion, preoperative PSA level of {>=}10 ng/ml, and omission of androgen deprivation (AD) were independent predictors for a reduced bRFS (p < 0.05). From the date of surgery, the median follow-up was 43 and 60 months for A-IMRT and S-IMRT, respectively. The 3-year bRFS rate for A-IMRT was 91% compared to 79% for S-IMRT (p < 0.05). On multivariate analysis, Gleason grades of {>=}4+3, perineural invasion, and omission of AD were independent predictors for a reduced bRFS (p < 0.05). S-IMRT was no longer an independent prognostic factor (p = 0.08). Conclusions: High-dose A-IMRT significantly improves 3-year bRFS compared to S-IMRT. Gleason grades of {>=}4+3, perineural invasion, and omission of AD were independent prognostic factors for a decreased bRFS, both from the dates of surgery and from radiotherapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Accelerated Partial Breast Irradiation for Pure Ductal Carcinoma in Situ

Purpose: To report outcomes for ductal carcinoma in situ (DCIS) treated with breast-conserving therapy using accelerated partial breast irradiation (APBI). Methods and Materials: From March 2001 to February 2009, 53 patients with Stage 0 breast cancer were treated with breast conserving surgery and adjuvant APBI. Median age was 62 years. All patients underwent excision with margins negative by {>=}1 mm before adjuvant radiotherapy (RT). A total of 39 MammoSite brachytherapy (MS) patients and 14 three-dimensional conformal external beam RT (3DCRT) patients were treated to the lumpectomy bed alone with 34 Gy and 38.5 Gy, respectively. Of the DCIS cases, 94% were mammographically detected. All patients with calcifications had either specimen radiography or postsurgical mammography confirmation of clearance. Median tumor size was 6 mm, and median margin distance was 5 mm. There were no statistically significant differences according to APBI method for race/ethnicity, tumor detection method, tumor grade, estrogen receptor (ER) status, or use of tamoxifen (p = NS). Recurrence and survival were calculated using the Kaplan-Meier method. Cosmesis was scored by the Harvard criteria. Results: With a median follow-up of 3.6 years (range, 0.4-6.3 years), the overall and cause-specific survival rates were 98% and 100%, respectively. Three-year actuarial ipsilateral breast tumor recurrence was 2%. One failure was observed at the resection bed 11 months post-RT. No other elsewhere breast failures, regional recurrences, or distant metastases were noted. Cosmesis was excellent or good in 92.4% of cases, with no statistically significant differences according to the APBI method (92.3% with MammoSite and 92.8% with 3DCRT; p = 0.649). Conclusions: APBI as part of breast-conserving therapy for pure DCIS was associated with excellent local control and survival rates, with the vast majority of patients having good to excellent cosmesis. This finding supports the recent analysis by the American Society of Breast Surgeons on a subset of DCIS patients treated efficaciously with APBI.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Long-Term Results of a Prospective, Phase II Study of Long-Term Androgen Ablation, Pelvic Radiotherapy, Brachytherapy Boost, and Adjuvant Docetaxel in Patients With High-Risk Prostate Cancer

Purpose: We report the long-term results of a prospective, Phase II study of long-term androgen deprivation (AD), pelvic radiotherapy (EBRT), permanent transperineal prostate brachytherapy boost (PB), and adjuvant docetaxel in patients with high-risk prostate cancer. Methods and Materials: Eligibility included biopsy-proven prostate adenocarcinoma with the following: prostate-specific antigen (PSA) > 20 ng/ml; or Gleason score of 7 and a PSA >10 ng/ml; or any Gleason score of 8 to 10; or stage T2b to T3 irrespective of Gleason score or PSA. Treatment consisted of 45 Gy of pelvic EBRT, followed 1 month later by PB with either iodine-125 or Pd-103. One month after PB, patients received three cycles of docetaxel chemotherapy (35 mg/m{sup 2} per week, Days 1, 8, and 15 every 28 days). All patients received 2 years of AD. Biochemical failure was defined as per the Phoenix definition (PSA nadir + 2). Results: From August 2000 to March 2004, 42 patients were enrolled. The median overall and active follow-ups were 5.6 years (range, 0.9-7.8 years) and 6.3 years (range, 4-7.8 years), respectively. Grade 2 and 3 acute genitourinary (GU) and gastrointestinal (GI) toxicities were 50.0% and 14.2%, respectively, with no Grade 4 toxicities noted. Grade 3 and 4 acute hematologic toxicities were 19% and 2.4%, respectively. Of the patients, 85.7% were able to complete the planned multimodality treatment. The 5- and 7-year actuarial freedom from biochemical failures rates were 89.6% and 86.5%, and corresponding rates for disease-free survival were 76.2% and 70.4%, respectively. The 5- and 7-year actuarial overall survival rates were 83.3% and 80.1%, respectively. The 5- and 7-year actuarial rates of late Grade 2 GI/GU toxicity (no Grade 3-5) was 7.7%. Conclusions: The trimodality approach of using 2 years of AD, external radiation, brachytherapy, and upfront docetaxel in high-risk prostate cancer is well tolerated, produces encouraging long-term results, and should be validated in a multi-institutional setting.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Prolongation of Total Treatment Time Because of Infrequently Missed Days of Treatment Is Not Associated With Inferior Biochemical Outcome After Dose-Escalated Radiation Therapy for Prostate Cancer

Purpose: Prolongation of treatment time with radiation therapy (RT) is associated with inferior disease control for many rapidly proliferating tumors, but it is uncertain whether the same effect is seen in prostate cancer. Methods and Materials: 596 patients underwent with curative-intent RT for adenocarcinoma of the prostate. By National Comprehensive Cancer Network criteria, men were classified as having low-risk (30%), medium-risk (40%), or high-risk (30%) disease. The median RT dose was 72 Gy. Androgen-deprivation therapy (ADT) was used in 45%. The idealized treatment time was defined as the total elapsed time (including weekends) to complete treatment if started on a Monday. Missed days of treatment, defined as the number of days beyond the idealized treatment time, was recorded for all patients. Missed days were added to the end of therapy resulting in a longer treatment time. Analysis was conducted for missed days and other standard prognostic variables against freedom from biochemical failure (FFBF). Results: The median number of missed days was 2 (range, -3 to 22). With a median follow-up of 51 months, men with 5 or more missed days had similar 4-year FFBF rates (79% vs. 83% in men with <5 missed days, p = 0.0809), especially in the subset of men receiving 74 Gy or greater (89% for both groups, p = 0.8008). Analysis of missed days was performed for the subsets of dose, ADT, and risk category. Men without ADT had a lower FFBF rate with more missed days (p = 0.0030), but this association was not seen in men treated to a dose of 74 Gy or greater (p = 0.7425). On multivariate analysis, dose (p = 0.0010), T stage (p = 0.0145), and prostate-specific antigen level (p < 0.0001) were associated with FFBF, but Gleason score (p = 0.1351) and missed days (p = 0.3767) were not. Conclusions: Slight prolongation of treatment time (e.g., {<=}7 days) was not associated with inferior FFBF, especially in men receiving an RT dose of 74 Gy or greater.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

2-Methoxyestradiol, an Endogenous Estrogen Metabolite, Sensitizes Radioresistant MCF-7/FIR Breast Cancer Cells Through Multiple Mechanisms

Purpose: The requirement for a well-tolerated and highly effective radiosensitizer that preferentially sensitizes tumor cells at multiple levels of radioresistance remains largely unmet. 2-Methoxyestradiol (2ME) has polypharmacological profiles that target multiple signaling pathways involved in the development of radioresistance. In the current study, we investigated the radiosensitizing effect of 2ME on the radioresistant breast cancer MCF-7/FIR cell line and explored the underlying mechanisms. Methods and Materials: The radiosensitizing effect of 2ME was evaluated on the basis of cell death and clonogenic survival. Formation of reactive oxygen species (ROS), apoptosis, and cell cycle progression were assessed by flow cytometry. Radiation-induced DNA damage was evaluated on the basis of histone {gamma}-H2AX phosphorylation and foci formation. Immunoblotting was used to assess the effects of {gamma} radiation and/or 2ME on radioresistance pathways. Results: Our data demonstrate that MCF-7/FIR cells expressed higher levels of Bcl-2 and HIF-1{alpha} and displayed a lower ROS phenotype than the parental MCF-7 cells. Treatment of parental MCF-7 cells with 2ME (0.5 {mu}M) had minimal effect on {gamma} radiation-induced cell proliferation and surviving fractions. On the contrary, in MCF-7/FIR cells, treatment with 2ME significantly enhanced {gamma} radiation-induced reduction in cell proliferation and surviving fraction. This combination was effective in activating apoptosis, arresting the cell cycle at the G{sub 2}/M phase, and increasing the level of {gamma} radiation-induced ROS and the number of {gamma}-H2AX foci. In addition, 2ME significantly ameliorated {gamma} radiation-induced expression of the HIF-1{alpha} transcription factor and its downstream targets AKT/mTOR. Conclusion: 2ME preferentially sensitizes radioresistant MCF-7/FIR cells to {gamma} radiation by targeting multiple signaling pathways involved in the development of radioresistance. This polypharmacological profile qualifies 2ME as a promising radiosensitizer in the treatment of radioresistant breast cancer cells and warrants systematic preclinical and clinical studies.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Outcomes of Breast Cancer Patients With Triple Negative Receptor Status Treated With Accelerated Partial Breast Irradiation

Purpose: Triple negative receptor status (TNRS) of patients undergoing breast-conserving therapy treated with whole-breast irradiation has been associated with increased distant metastasis and decreased disease-free and overall survival. This paper reports the outcomes of TNRS patients treated with accelerated partial breast irradiation (APBI). Methods and Materials: We studied 455 patients who received APBI at our institution, using interstitial, intracavitary, and three-dimensional conformal radiation therapy. TNRS was assigned if a patient tested negative for all three (ER [estrogen receptor], PR [progesterone receptor], and HER2/neu) receptors. Of 202 patients with all receptor results available, 20 patients were designated TNRS, and 182 patients had at least one receptor positive (RP). We analyzed ipsilateral breast tumor recurrence (IBTR), regional nodal failure (RNF), distant metastasis (DM), and overall survival (OS). Results: Mean follow-up was 4.1 years for the TNRS group and 5.1 years for the RP cohort (p = 0.11). TNRS patients had a higher histologic grade (59% TNRS vs. 13% RP; p < 0.001). Mean tumor size, stage N1 disease, and margin status were similar. Based on a 5-year actuarial analysis, the TNRS cohort experienced no IBTR, RNF, or DM, with an OS of 100% versus rates of 1.4% IBTR, 1.5% RNF, and 2.8% DM in the RP cohort (p > 0.52). OS for the RP cohort was 93% at 5 years (p > 0.28). Conclusions: In our patient population, TNRS conferred a clinical outcome similar to that of patients with RP disease treated with APBI. Further investigation with larger patient populations and longer follow-up periods is warranted to confirm that APBI is a safe and effective treatment for patients with localized TNRS breast cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

The Percent of Positive Biopsy Cores Improves Prediction of Prostate Cancer-Specific Death in Patients Treated With Dose-Escalated Radiotherapy

Purpose: To examine the prognostic utility of the percentage of positive cores (PPC) at the time of prostate biopsy for patients treated with dose-escalated external beam radiation therapy. Methods and Materials: We performed a retrospective analysis of patients treated at University of Michigan Medical Center to at least 75 Gy. Patients were stratified according to PPC by quartile, and freedom from biochemical failure (nadir + 2 ng/mL), freedom from metastasis (FFM), cause-specific survival (CSS), and overall survival (OS) were assessed by log-rank test. Receiver operator characteristic (ROC) curve analysis was used to determine the optimal cut point for PPC stratification. Finally, Cox proportional hazards multivariate regression was used to assess the impact of PPC on clinical outcome when adjusting for National Comprehensive Cancer Network (NCCN) risk group and androgen deprivation therapy. Results: PPC information was available for 651 patients. Increasing-risk features including T stage, prostate-specific antigen, Gleason score, and NCCN risk group were all directly correlated with increasing PPC. On log-rank evaluation, all clinical endpoints, except for OS, were associated with PPC by quartile, with worse clinical outcomes as PPC increased, with the greatest impact seen in the highest quartile (>66.7% of cores positive). ROC curve analysis confirmed that a cut point using two-thirds positive cores was most closely associated with CSS (p = 0.002; area under ROC curve, 0.71). On univariate analysis, stratifying patients according to PPC less than or equal to 66.7% vs. PPC greater than 66.7% was prognostic for freedom from biochemical failure (p = 0.0001), FFM (p = 0.0002), and CSS (p = 0.0003) and marginally prognostic for OS (p = 0.055). On multivariate analysis, after adjustment for NCCN risk group and androgen deprivation therapy use, PPC greater than 66.7% increased the risk for biochemical failure (p = 0.0001; hazard ratio [HR], 2.1 [95% confidence interval (CI), 1.4-3.0]) and FFM (p = 0.05; HR, 1.7 [95% CI, 1.1-2.9]) and marginally increased the risk for CSS (p = 0.057; HR, 2.1 [95% CI, 1.0-4.6]). Conclusion: PPC at the time of biopsy adds prognostic value for clinically meaningful endpoints for patients treated with dose-escalated radiation therapy. This was particularly true for NCCN-defined intermediate- and high-risk patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

MLN8054, A Small Molecule Inhibitor of Aurora Kinase A, Sensitizes Androgen-Resistant Prostate Cancer to Radiation;Aurora kinase A; MLN8054; Prostate cancer; Radiation

Purpose: To determine whether MLN8054, an Aurora kinase A (Aurora-A) inhibitor causes radiosensitization in androgen-insensitive prostate cancer cells in vitro and in vivo. Methods and Materials: In vitro studies consisted of culturing PC3 and DU145 prostate cancer cells and then immunoblotting Aurora A and phospho-Aurora A after radiation and/or nocodazole with MLN8054. Phases of the cell cycle were measured with flow cytometry. PC3 and DU145 cell lines were measured for survival after treatment with MLN8054 and radiation. Immunofluorescence measured {gamma}-H2AX in the PC3 and DU145 cells after treatment. In vivo studies looked at growth delay of PC3 tumor cells in athymic nude mice. PC3 cells grew for 6 to 8 days in mice treated with radiation, MLN8054, or combined for 7 more days. Tumors were resected and fixed on paraffin and stained for von Willebrand factor, Ki67, and caspase-3. Results: In vitro inhibition of Aurora-A by MLN8054 sensitized prostate cancer cells, as determined by dose enhancement ratios in clonogenic assays. These effects were associated with sustained DNA double-strand breaks, as evidenced by increased immunofluorescence for {gamma}-H2AX and significant G2/M accumulation and polyploidy. In vivo, the addition of MLN8054 (30 mg/kg/day) to radiation in mouse prostate cancer xenografts (PC3 cells) significantly increased tumor growth delay and apoptosis (caspase-3 staining), with reduction in cell proliferation (Ki67 staining) and vascular density (von Willebrand factor staining). Conclusion: MLN8054, a novel small molecule Aurora-A inhibitor showed radiation sensitization in androgen-insensitive prostate cancer in vitro and in vivo. This warrants the clinical development of MLN8054 with radiation for prostate cancer patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Leptin deficiency-induced obesity exacerbates ultraviolet B radiation-induced cyclooxygenase-2 expression and cell survival signals in ultraviolet B-irradiated mouse skin

Obesity has been implicated in several inflammatory diseases and in different types of cancer. Chronic inflammation induced by exposure to ultraviolet (UV) radiation has been implicated in various skin diseases, including melanoma and nonmelanoma skin cancers. As the relationship between obesity and susceptibility to UV radiation-caused inflammation is not clearly understood, we assessed the role of obesity on UVB-induced inflammation, and mediators of this inflammatory response, using the genetically obese (leptin-deficient) mouse model. Leptin-deficient obese (ob/ob) mice and wild-type counterparts (C57/BL6 mice) were exposed to UVB radiation (120 mJ/cm{sup 2}) on alternate days for 1 month. The mice were then euthanized and skin samples collected for analysis of biomarkers of inflammatory responses using immunohistochemistry, western blotting, ELISA and real-time PCR. Here, we report that the levels of inflammatory responses were higher in the UVB-exposed skin of the ob/ob obese mice than those in the UVB-exposed skin of the wild-type non-obese mice. The levels of UVB-induced cyclooxygenase-2 expression, prostaglandin-E{sub 2} production, proinflammatory cytokines (i.e., tumor necrosis factor-alpha, interleukin-1beta, interleukin-6), and proliferating cell nuclear antigen and cell survival signals (phosphatidylinositol-3-kinase and p-Akt-Ser{sup 473}) were higher in the skin of the ob/ob obese mice than the those in skin of their wild-type non-obese counterparts. Compared with the wild-type non-obese mice, the leptin-deficient obese mice also exhibited greater activation of NF-kappaB/p65 and fewer apoptotic cells in the UVB-irradiated skin. Our study suggests for the first time that obesity in mice is associated with greater susceptibility to UVB-induced inflammatory responses and, therefore, obesity may increase susceptibility to UVB-induced inflammation-associated skin diseases, including the risk of skin cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

Cross-talk between non-genomic and genomic signalling pathways - Distinct effect profiles of environmental estrogens

Estrogen receptor (ER) transcriptional cross-talk after activation by 17{beta}-estradiol (E2) has been studied in considerable detail, but comparatively little is known about the ways in which synthetic estrogen-like chemicals, so-called xenoestrogens, interfere with these signalling pathways. E2 can stimulate rapid, non-genomic signalling events, such as activation of the Src/Ras/Erk signalling pathway. We investigated how activation of this pathway by E2, the estrogenic environmental contaminants o,p'-DDT, {beta}-HCH and p,p'-DDE, and epidermal growth factor (EGF) influences the expression of ER target genes, such as TFF1, ER, PR, BRCA1 and CCND1, and the proliferation of breast cancer cells. Despite commonalities in their estrogenicity as judged by cell proliferation assays, the environmental contaminants exhibited striking differences in their non-genomic and genomic signalling. The gene expression profiles of o,p'-DDT and {beta}-HCH resembled the effects observed with E2. In the case of {beta}-HCH this is surprising, considering its reported lack of affinity to the 'classical' ER. The expression profiles seen with p,p'-DDE showed some similarities with E2, but overall, p,p'-DDE was a fairly weak transcriptional inducer of TFF1, ER, PR, BRCA1 and CCND1. We observed distinct differences in the non-genomic signalling of the tested compounds. p,p'-DDE was unable to stimulate Src and Erk1/Erk2 activations. The effects of E2 on Src and Erk1/Erk2 phosphorylation were transient and weak when compared to EGF, but {beta}-HCH induced strong and sustained activation of all tested kinases. Transcription of TFF1, ER, PR and BRCA1 by E2, o,p'-DDT and {beta}-HCH could be suppressed partially by inhibiting the Src/Ras/Erk pathway with PD 98059. However, this was not seen with p,p'-DDE. Our investigations show that the cellular activities of estrogens and xenoestrogens are the result of a combination of extranuclear (non-genomic) and nuclear (genomic) events and highlight the need to take non-genomic effects and signalling cross-talk into consideration, when screening for environmental estrogens. Otherwise, chemicals devoid of ER affinity, such as {beta}-HCH, but with an effect profile otherwise similar to estrogens might be overlooked in safety testing.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

Effects of arecoline on adipogenesis, lipolysis, and glucose uptake of adipocytes-A possible role of betel-quid chewing in metabolic syndrome

To investigate the possible involvement of betel-quid chewing in adipocyte dysfunction, we determined the effects of arecoline, a major alkaloid in areca nuts, on adipogenic differentiation (adipogenesis), lipolysis, and glucose uptake by fat cells. Using mouse 3T3-L1 preadipocytes, we showed that arecoline inhibited adipogenesis as determined by oil droplet formation and adipogenic marker gene expression. The effects of arecoline on lipolysis of differentiated 3T3-L1 adipocytes were determined by the glycerol release assay, indicating that arecoline induced lipolysis in an adenylyl cyclase-dependent manner. The diabetogenic effects of arecoline on differentiated 3T3-L1 adipocytes were evaluated by the glucose uptake assay, revealing that {>=} 300 {mu}M arecoline significantly attenuated insulin-induced glucose uptake; however, no marked effect on basal glucose uptake was detected. Moreover, using 94 subjects that were randomly selected from a health check-up, we determined the association of betel-quid chewing with hyperlipidemia and its related risk factors. Hyperlipidemia frequency and serum triglyceride levels of betel-quid chewers were significantly higher than those of non-betel-quid chewers. In this study, we demonstrated that arecoline inhibits adipogenic differentiation, induces adenylyl cyclase-dependent lipolysis, and interferes with insulin-induced glucose uptake. Arecoline-induced fat cell dysfunction may lead to hyperlipidemia and hyperglycemia/insulin-resistance. These findings provide the first in vitro evidence of betel-quid chewing modulation of adipose cell metabolism that could contribute to the explanation of the association of this habit with metabolic syndrome disorders.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

Pharmacokinetics of bisphenol A in neonatal and adult Sprague-Dawley rats

Bisphenol A (BPA) is an important industrial chemical used in the manufacture of polycarbonate plastic products and epoxy resin-based food can liners. The presence of BPA in urine of > 90% of Americans aged 6-60 suggests ubiquitous and frequent exposure. The current study used LC/MS/MS to measure serum pharmacokinetics of aglycone (active) and conjugated (inactive) BPA in adult and neonatal Sprague-Dawley rats by oral and injection routes. Deuterated BPA was used to avoid issues of background contamination. Linear pharmacokinetics were observed in adult rats treated orally in the range of 0-200 {mu}g/kg bw. Evidence for enterohepatic recirculation of conjugated, but not aglycone, BPA was observed in adult rats. Significant inverse relationships were observed between postnatal age and measures of internal exposures to aglycone BPA and its elimination. In neonatal rats treated orally, internal exposures to aglycone BPA were substantially lower than from subcutaneous injection. The results reinforce the critical role for first-pass Phase II metabolism of BPA in gut and liver after oral exposure that attenuates internal exposure to the aglycone form in rats of all ages. The internal exposures to aglycone BPA observed in adult and neonatal rats following a single oral dose of 100 {mu}g/kg bw are inconsistent with effects mediated by classical estrogen receptors based on binding affinities. However, an impact on alternative estrogen signaling pathways that have higher receptor affinity cannot be excluded in neonatal rats. These findings emphasize the importance of matching aglycone BPA internal dosimetry with receptor affinities in experimental animal studies reporting toxicity.

60 APPLIED LIFE SCIENCES↗