Publications by authors named "Amar Kishan"

It has been shown that magnetic resonance imaging (MRI) guidance versus computed tomography (CT) guidance for aggressive margin-reduction (AMR) for stereotactic body radiotherapy (SBRT) in prostate cancer reduces acute toxicity, but the longer-term benefits are unknown. We performed a secondary analysis of MIRAGE, a phase 3 randomized clinical trial of MRI-guided SBRT for prostate cancer, to determine whether AMR with MRI guidance significantly reduced 2-yr physician-scored or patient-reported toxic effects in comparison to CT guidance. The cumulative incidence of 2-yr physician-scored toxicity, defined as grade ≥2 genitourinary (GU) and gastrointestinal (GI) toxic effects according to Common Terminology Criteria for Adverse Events v4.

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Importance: Preclinical studies suggest that exposure to prostate-directed local therapy (LT) may influence the efficacy of subsequent systemic therapy including androgen receptor pathway inhibitors. However, there is insufficient clinical evidence to support this premise in patients with nonmetastatic castrate-resistant prostate cancer (nmCRPC).

Objective: To determine whether exposure to prior prostate-directed LT (radical prostatectomy [RP], radiation therapy [RT], or both) played any effect-modifying role in the treatment effect of apalutamide on metastasis-free survival (MFS) and overall survival (OS) in patients with nmCRPC.

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Background And Objective: Local intraprostatic radiorecurrence of prostate cancer (IPR-PC) can be associated with an aggressive natural history and impact long-term disease-specific survival. While appropriate local salvage intervention can be curative, best practices for workup and local salvage of intraprostatic recurrence are poorly defined. The American Radium Society (ARS) Genitourinary Appropriate Use Criteria Committee sought to develop evidence-based recommendations to address this gap.

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Background And Objective: Time to testosterone recovery (TR) following androgen deprivation therapy (ADT) with gonadotropin-releasing hormone agonists varies widely. We evaluate TR kinetics and the oncological impact of an effective castration period in patients receiving definitive radiotherapy and ADT for prostate cancer.

Methods: We obtained individual patient data from randomized controlled trials of radiotherapy with ADT and prospectively collected serial testosterone data from the MARCAP Consortium.

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Background And Objective: We characterized tumor prostate-specific membrane antigen (PSMA) levels as a reflection of cancer biology and treatment sensitivities for treatment-naïve prostate cancer.

Methods: We first correlated PSMA positron emission tomography (PET) maximum standardized uptake values (SUVmax) in primary prostate cancer with tumor FOLH1 (PSMA RNA abundance) to establish RNA as a proxy (n = 55). We then discovered and validated molecular pathways associated with PSMA RNA levels in two large primary tumor cohorts.

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Purpose: Intraprostatic recurrence (IRR) of prostate cancer after radiation therapy is increasingly identified. Our objective was to review the literature to determine the optimal workup for identifying IRR, the management options, and practical considerations for the delivery of re-irradiation as salvage local therapy.

Methods: We performed a systematic review of available publications and ongoing studies on the topics of IRR, with a focus on salvage re-irradiation.

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Background: We performed an exploratory analysis of the SPARTAN trial to determine whether concomitant exposure to several classes of commonly prescribed medications influenced the effect of apalutamide on overall survival (OS) and metastasis-free survival (MFS) in patients with non-metastatic castration-resistant prostate cancer (nmCRPC).

Patients And Methods: SPARTAN was a phase III randomized controlled trial in which nmCRPC patients were randomly assigned in a 2:1 ratio to receive androgen deprivation therapy with or without apalutamide. We focused on 5 commonly prescribed classes of medications: metformin, statins, angiotensin converting enzyme inhibitors (ACEI), acetylsalicylic acid (ASA), and proton pump inhibitors (PPI) based on a plausible biological and clinical rationale.

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Introduction: To date, radio-recurrent prostate cancer (PCa) ranks as the fourth most common urological malignancy when considering the number of men with localized PCa who undergo radiation treatment and subsequently experience a biochemical recurrence. This systematic review aimed to summarize available evidence about the outcomes of local salvage strategies in patients with local PCa recurrence following primary external-beam radiation therapy (EBRT).

Methods: We conducted a comprehensive bibliographic search on MEDLINE, Scopus, and Web of Science Core Collection databases in October 2023 to identify studies published in the last 20 years evaluating outcomes of local salvage procedures in patients with locally radio-recurrent PCa following EBRT.

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Unlabelled: Prostate cancer is frequently treated with radiotherapy. Unfortunately, aggressive radioresistant relapses can arise, and the molecular underpinnings of radioresistance are unknown. Modern clinical radiotherapy is evolving to deliver higher doses of radiation in fewer fractions (hypofractionation).

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Systemic treatments for metastatic castration-resistant prostate cancer (mCRPC) include androgen deprivation therapy, androgen receptor pathway inhibitors, chemotherapy, and radiopharmaceuticals, all of which have associated toxicity. Prostate-specific membrane antigen (PSMA) PET/CT allows for higher sensitivity in detecting metastatic disease than is possible with conventional imaging. We hypothesized that PSMA PET/CT-guided, metastasis-directed radiotherapy may offer durable disease control with low toxicity rates in patients with mCRPC who have a limited number of metastases.

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Purpose: Early PSA response has been found to be prognostic of outcomes in metastatic hormone sensitive prostate cancer. We performed a secondary analysis of the TITAN trial to determine if early PSA response was predictive of treatment efficacy in metastatic hormone sensitive prostate cancer patients.

Materials And Methods: Early PSA response was defined as achieving a PSA level of ≤ 0.

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Purpose: To characterize the relationship between Decipher genomic classifier scores and prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-based metastatic spread.

Materials And Methods: We identified patients from four institutions who underwent PSMA PET/CT scans pretreatment for primary staging or postradical prostatectomy (RP) for suspected recurrence and had Decipher transcriptomic data available from biopsy or RP specimens. PSMA PET/CT-based patterns of spread were classified as localized (miT + N0M0) or nonlocalized (miN1M0 or miM1a-c).

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Background And Objective: Adherence to guideline recommendations can improve the quality of care for patients with prostate cancer (PCa). Our aim was to assess adherence to guidelines for locoregional PCa by international region.

Methods: The study cohort comprised patients diagnosed with locoregional PCa in the 10-country Movember TrueNTH Global Registry (n = 62 688; 2013-2022).

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Purpose: This systematic review provides an overview of literature on the impact of magnetic resonance-guided radiation therapy (MRgRT) on patient-reported outcomes (PROs) in patients with prostate cancer (PC).

Methods And Materials: A systematic search was performed in October 2023 in PubMed, EMBASE, and Cochrane Library. The Patient, Intervention, Comparison, Outcomes, and Study design (PICOS) framework was used to determine eligibility criteria.

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Article Synopsis
  • * Recent updates to the NCCN Guidelines for Bladder Cancer reflect changes from the fifth edition of the WHO Classification of Tumours, ensuring alignment with new standards.
  • * The guidelines also introduce new treatment options for NMIBC that doesn't respond to bacillus Calmette-Guérin (BCG) therapy and provide updated recommendations for systemic therapy targeting advanced or metastatic bladder cancer.
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Purpose: Guidelines recommend adding androgen-deprivation therapy (ADT) to radiation therapy (RT) in certain patients with localized prostate cancer. Individualized genomic testing may improve the prognostic accuracy of risk assessments. Herein, we describe a mathematical model of the benefit of adding ADT to RT as a function of the personalized clinical cell-cycle risk (CCR) score to inform 10-year metastasis risk.

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This multicenter randomized phase III trial (NCT04457245) evaluated the effect of performing prostate-specific membrane antigen (PSMA) PET/CT before definitive radiotherapy. Men with unfavorable intermediate- or high-risk prostate cancer were randomized 1.08:1 between receiving and not receiving a PSMA PET/CT scan before definitive radiotherapy.

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Background And Purpose: Magnetic Resonance Imaging (MRI)-guided Stereotactic body radiotherapy (SBRT) treatment to prostate bed after radical prostatectomy has garnered growing interests. The aim of this study is to evaluate intra-fractional anatomic and dose/volume metric variations for patients receiving this treatment.

Materials And Methods: Nineteen patients who received 30-34 Gy in 5 fractions on a 0.

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Introduction/background: Phosphatase and tensin homolog (PTEN) genomic deletions and transmembrane protease, serine 2/v-ets avian erthyroblastosis virus E26 oncogene homolog (ERG) rearrangements are two of the most common genetic abnormalities associated with prostate cancer. Prior studies have demonstrated these alterations portend worse clinical outcomes. Our objective is to evaluate the impact of biopsy-determined PTEN losses and TMPRSS2-ERG fusion on biochemical progression-free survival (bPFS) and overall survival (OS) in patients who receive SBRT for localized prostate cancer.

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Background And Objective: The utility of prostate radiotherapy (RT) is unclear in men with metastatic hormone-sensitive prostate cancer (mHSPC) receiving intensified systemic therapy with androgen deprivation therapy (ADT) and androgen receptor pathway inhibitors (ARPIs). We performed a network meta-analysis of randomized controlled trials (RCTs) to investigate the role of prostate RT in low-volume mHSPC.

Methods: Bibliographic databases and conference proceedings were searched through July 2023 for RCTs evaluating the addition of ARPIs or prostate RT to standard of care (SOC) systemic therapy, defined as ADT or ADT plus docetaxel, for the initial treatment of mHSPC.

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Nearly all men with metastatic hormone-sensitive prostate cancer treated with intermittent androgen deprivation therapy (ADT) experience recurrence within 6 mo of testosterone recovery. We conducted a single-arm phase 2 trial to evaluate whether addition of dual androgen receptor pathway inhibitors (ARPIs) and metastasis-directed stereotactic body radiotherapy (SBRT) to intermittent ADT improves recurrence rates for men with between one and five nonvisceral, extrapelvic metastases on prostate-specific membrane antigen positron emission tomography/computed tomography after prior radical prostatectomy. Patients received 6 mo of androgen annihilation therapy (AAT; leuprolide, abiraterone acetate plus prednisone, and apalutamide) and metastasis-directed SBRT.

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Purpose: Treatment intensification of external beam radiotherapy (EBRT) plays a crucial role in the treatment of high-risk prostate cancer.

Methods: We performed a critical narrative review of the relevant literature and present new developments in evidence-based treatment intensification strategies.

Results: For men with high-risk prostate cancer, there is strong evidence to support prolonging androgen deprivation therapy (ADT) to 18-36 months and escalating the dose to the prostate using a brachytherapy boost.

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