First Report of NRG Oncology/Radiation Therapy Oncology Group 0622: A Phase 2 Trial of Samarium-153 Followed by Salvage Prostatic Fossa Irradiation in High-Risk Clinically Nonmetastatic Prostate Cancer After Radical Prostatectomy.

PURPOSE: To investigate the utility of 153Sm lexidronam (Quadramet) in the setting of men with prostate cancer status post radical prostatectomy who develop biochemical failure with no clinical evidence of osseous metastases. PATIENTS AND METHODS: Trial NRG Oncology RTOG 0622 is a single-arm phase 2 trial that enrolled men with pT2-T4, N0-1, M0 prostate cancer status post radical prostatectomy, who meet at least 1 of these biochemical failure criteria: (1) prostate-specific antigen (PSA) \u3e 1.0 ng/mL; (2) PSA \u3e 0.2 ng/mL if Gleason score 9 to 10; or (3) PSA \u3e 0.2 ng/mL if N1. Patients received 153Sm (2.0 mCi/kg intravenously × 1) followed by salvage external beam radiation therapy (EBRT) to the prostatic fossa (64.8-70.2 Gy in 1.8-Gy daily fractions). No androgen deprivation therapy was allowed. The primary objective was PSA response within 12 weeks of receiving 153Sm. The secondary objectives were to: (1) assess the completion rate for the regimen of 153Sm and EBRT; (2) evaluate the hematologic toxicity and other adverse events (AEs) at 12 and 24 weeks; and (3) determine the freedom from progression rate at 2 years. RESULTS: A total of 60 enrolled eligible patients were included in this analysis. Median follow-up was 3.97 years. A PSA response was achieved in 7 of 52 evaluable patients (13.5%), compared with the 25% hypothesized. The 2-year freedom from progression rate was 25.5% (95% confidence interval 14.4%-36.7%), and the biochemical failure rate was 64.4% (95% CI 50.5%-75.2%). Samarium-153 was well tolerated, with 16 (of 60) grade 3 to 4 hematologic AEs and no grade 5 hematologic AEs. Radiation therapy was also well tolerated, with no grade 3 to 5 acute radiation therapy-related AEs and 1 grade 3 to 4 and no grade 5 late radiation therapy-related AEs. CONCLUSIONS: Trial NRG Oncology RTOG 0622 did not meet its primary endpoint of PSA response, although the regimen of 153Sm and salvage EBRT was well tolerated. Although the toxicity profile supports study of 153Sm in high-risk disease, it may not be beneficial in men receiving EBRT

Novel actions of next-generation taxanes benefit advanced stages of prostate cancer.

PURPOSE: To improve the outcomes of patients with castration-resistant prostate cancer (CRPC), there is an urgent need for more effective therapies and approaches that individualize specific treatments for patients with CRPC. These studies compared the novel taxane cabazitaxel with the previous generation docetaxel, and aimed to determine which tumors are most likely to respond. EXPERIMENTAL DESIGN: Cabazitaxel and docetaxel were compared via in vitro modeling to determine the molecular mechanism, biochemical and cell biologic impact, and cell proliferation, which was further assessed ex vivo in human tumor explants. Isogenic pairs of RB knockdown and control cells were interrogated in vitro and in xenograft tumors for cabazitaxel response. RESULTS: The data herein show that (i) cabazitaxel exerts stronger cytostatic and cytotoxic response compared with docetaxel, especially in CRPC; (ii) cabazitaxel induces aberrant mitosis, leading to pyknotic and multinucleated cells; (iii) taxanes do not act through the androgen receptor (AR); (iv) gene-expression profiling reveals distinct molecular actions for cabazitaxel; and (v) tumors that have progressed to castration resistance via loss of RB show enhanced sensitivity to cabazitaxel. CONCLUSIONS: Cabazitaxel not only induces improved cytostatic and cytotoxic effects, but also affects distinct molecular pathways, compared with docetaxel, which could underlie its efficacy after docetaxel treatment has failed in patients with CRPC. Finally, RB is identified as the first potential biomarker that could define the therapeutic response to taxanes in metastatic CRPC. This would suggest that loss of RB function induces sensitization to taxanes, which could benefit up to 50% of CRPC cases

Costs of Early Adjuvant Radiation Therapy After Radical Prostatectomy: A Decision Analysis

Purpose/Objective(s): Prospective, randomized trials support adjuvant radiation therapy (RT) for adverse pathologic features after radical prostatectomy (RP). However, adjuvant RT is not universally delivered in this setting. Criticisms of adjuvant RT include toxicity, financial costs, potential overtreatment, and effectiveness of salvage RT. The objective of this study was to construct a decision analytic model to estimate real world cost of RT vs. no RT within the context of the effectiveness of early adjuvant RT for prostate patients based on published clinical results of the Southwest Oncology Group prospective trial of adjuvant RT (SWOG 8794). American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C

IGRT After Prostatectomy: Evaluation of Corrective Shifts and Toxicity Using Online Cone Beam CT vs. Weekly Port Films for Target Localization

Purpose/Objective(s): Image guidance (IG) may permit higher radiotherapy (RT) doses (\u3e65 Gy) after radical prostatectomy (RP) without increased toxicity, with improved accuracy and smaller margins. Conebeam (CBCT) allows IGRT with volumetric images. This study evaluated CBCT shifts and toxicity after conformal IGRT, compared to RT with port films. American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C

Simple Frameshifts in MIS Postoperative Pain Management Significantly Reduce Opiate Prescriptions

Aims for Improvement The intervention aimed to reduce narcotics provided to patients after MIS by reducing number of narcotic prescriptions and amount prescribed by 25% without affecting patientreported pain scores Usage measured in Morphine Equivalent Doses (MED) MED and pain score assessed at 3 time points: post-op day 1 (POD1), discharge (D/C) and follow-up (FU) apt Pre- and Post-intervention cohorts - Month 1 (Pre-intervention): 21 patients and Month 2 (Post-intervention): 30 patient

PARP-1 regulates DNA repair factor availability.

PARP-1 holds major functions on chromatin, DNA damage repair and transcriptional regulation, both of which are relevant in the context of cancer. Here, unbiased transcriptional profiling revealed the downstream transcriptional profile of PARP-1 enzymatic activity. Further investigation of the PARP-1-regulated transcriptome and secondary strategies for assessing PARP-1 activity in patient tissues revealed that PARP-1 activity was unexpectedly enriched as a function of disease progression and was associated with poor outcome independent of DNA double-strand breaks, suggesting that enhanced PARP-1 activity may promote aggressive phenotypes. Mechanistic investigation revealed that active PARP-1 served to enhance E2F1 transcription factor activity, and specifically promoted E2F1-mediated induction of DNA repair factors involved in homologous recombination (HR). Conversely, PARP-1 inhibition reduced HR factor availability and thus acted to induce or enhance BRCA-ness . These observations bring new understanding of PARP-1 function in cancer and have significant ramifications on predicting PARP-1 inhibitor function in the clinical setting

Potential for Dose-escalation in the Post-prostatectomy Setting with Intensitymodulated Radiation Therapy: A Dosimetric Study Using EORTC Consensus Guidelines for Target Volume Contours

Purpose: Radiation therapy (RT) is delivered after radical prostatectomy (RP) for prostate cancer (PC). Although intensity modulated radiation therapy (IMRT) has become standard in definitive RT for PC, dosimetric data in support of post-RP IMRT are limited. This study was designed to quantify benefits of IMRT versus 3D conformal RT (3DCRT) with respect to dose sparing of rectum and bladder and target volume coverage. Motivated by the desire to deliver higher radiation doses and to quantify the dosimetric impact of IMRT, we retrospectively analyzed images in order to: 1) identify a preferred IMRT beam arrangement; 2) evaluate the dosimetric advantages of IMRT compared to 3DCRT; and 3) assess the variation of dosimetric parameters during the RT course using conebeam CT (CBCT) images. American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C