Mohamad E Allaf

Mohamad E Allaf
Johns Hopkins Medicine | JHUSOM · Department of Urology

About

491
Publications
26,415
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12,399
Citations
Citations since 2017
175 Research Items
7771 Citations
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201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
Additional affiliations
January 2006 - present
Johns Hopkins Medicine
Position
  • Director, Minimally Invasive and Robotic Surgeyr

Publications

Publications (491)
Article
Background Renal cell carcinoma (RCC) can exhibit a unique vascular tropism that enables tumor thrombus extension into the inferior vena cava (IVC). While most RCC subtypes that form tumor thrombi are of clear cell (cc) histology, non–clear cell (ncc) subtypes can also exhibit this unique growth pattern. Objective To characterize clinicopathologic...
Article
Background: Active surveillance (AS) with the possibility of delayed intervention (DI) is emerging as a safe alternative to immediate intervention for many patients with small renal masses (SRMs). However, limited comparative data exist to inform the most appropriate management strategy for SRMs. Methods: Decision analytic Markov modeling was pe...
Article
Full-text available
Multimodal therapies were combined to eradicate the primary site, metastatic, and micrometastatic disease in men with newly diagnosed, synchronous, oligometastatic prostate cancer. The investigation included companion, phase II studies: total eradication therapy-1 (TET-1) for those treatment-naïve and total eradication therapy-2 (TET-2) for those p...
Preprint
Due to their immunosuppressive role, tumor-infiltrating regulatory T cells (TI-Tregs) represent attractive therapeutic targets. Analysis of TI vs. peripheral Tregs (P-Tregs) from 36 patients, across four malignancies, identified 17 candidate Master Regulators (MRs), predicted to mechanistically regulate TI-Tregs transcriptional state. In vivo , poo...
Article
296 Background: The incidence of renal cell carcinoma (RCC) has gradually increased over the past decades, particularly among African Americans (AA). Lifestyle and other factors such as high blood pressure and tobacco exposure are associated with its incidence. We aim to compare differences in clinicopathologic characteristics and survival outcomes...
Article
295 Background: Patients with small renal masses (SRM) can be managed conservatively by active surveillance (AS) or active treatment. A subset of patients who elect for AS undergo delayed intervention, either due to progression or other factors. Using a large, prospective registry of patients with SRMs we characterize differences in SRM growth traj...
Article
Objective: To develop a structured and objective scoring tool for assessment of robot assisted partial nephrectomy (RAPN): Scoring for Partial Nephrectomy (SPaN). Materials and methods: Content development: RAPN was deconstructed into 6 domains by a multi-institutional panel of 10 expert robotic surgeons. Performance on each domain was represent...
Article
Objective Judicious opioid stewardship would match each patient's prescription to their true medical necessity. However, most prescribing paradigms apply preset quantities and clinical judgment without objective data to predict individual use. We evaluated individual patient and in-hospital parameters as predictors of post-discharge opioid utilizat...
Article
Background: This study evaluated the utility of self-reported quality of life (QOL) metrics in predicting mortality among all-comers with renal cell carcinoma (RCC) and externally tested the findings in a registry of patients with small renal masses. Methods: The Surveillance, Epidemiology, and End Results-Medicare Health Outcomes Survey (SEER-M...
Article
Transperineal prostate biopsy carries a significantly lower risk of infectious complications compared with the transrectal approach. We provide a step-by-step description of our current procedural technique for performing transperineal prostate biopsy under local anesthesia. A key component of our technique is the use of a disposable, probe-mounted...
Article
Introduction The role of renal biopsy prior to surgical intervention for a renal mass remains controversial despite the fact that for all other urological organs except the testicle, biopsy inevitably precedes treatment as is true for all other specialties dealing with solid masses (e.g. thyroid, breast, colon, liver, etc.). Accordingly, we sought...
Article
Full-text available
T-cell receptor sequencing (TCRseq) enables tracking of T-cell clonotypes recognizing the same antigen over time and across biological compartments. TCRseq has been used to test if cross-reactive antitumor T cells are responsible for development of immune-related adverse events (irAEs) following immune checkpoint blockade. Prior studies have interp...
Article
Full-text available
Purpose: To evaluate the association of post-RP drain placement with post-operative complications and opioid use at a high-volume institution. Methods: A prospective, comparative cohort study of patients undergoing robot-assisted or open RP was conducted. Patients for two surgeons did not routinely receive pelvic drains ("No Drain" arm), while t...
Article
TPS4596 Background: There is no standard adjuvant systemic therapy that increases overall survival (OS) over surgery alone for non-metastatic RCC. Anti-PD-1 nivolumab (nivo) improves OS in metastatic RCC and is well tolerated. In mouse models, priming the immune system prior to surgery with anti-PD-1 results in superior OS compared to adjuvant dosi...
Article
Full-text available
In this report we describe our successful adoption of a single-use, probe-mounted, needle guide for perirectal hydrogel spacer placement prior to radiation therapy for prostate cancer. Use of this device eliminates the need for a mechanical stepper unit and facilitates perirectal hydrogel placement by ensuring alignment of the injection needle with...
Article
Neoadjuvant immune checkpoint blockade represents a novel approach for potentially decreasing the risk of recurrence in patients with nonmetastatic renal cell carcinoma (RCC). In this early phase clincal tiral, we evaluated the safety and tolerability of neoadjuvant treatment with the programmed cell death protein 1 (PD-1) inhibitor nivolumab in pa...
Article
Purpose Provider and hospital factors influence healthcare quality, but data are lacking to assess their impact on renal cancer surgery. We aimed to assess factors related to surgeon and hospital volume and study their impact on 30-day outcomes after radical nephrectomy. Materials and Methods Renal surgery data were abstracted from Maryland's Heal...
Article
Objective: To evaluate outcomes for patients with local recurrence (LR) of clinically localized renal cell carcinoma (RCC) without concurrent systemic metastasis from our institution, an event that occurs rarely (1-3%) after surgery. LR may be a harbinger of poor outcomes, and the best management of these patients is unclear. Materials/methods:...
Article
Full-text available
The objectives were to evaluate the safety and oncologic efficacy of primary robotic retroperitoneal lymph node (R-RPLND) dissection for testicular germ cell tumors. A retrospective analysis was performed on all primary R-RPLND cases performed by a single surgeon, who performs both open and R-RPLND at a high-volume academic institution, between Aug...
Article
Full-text available
Clinical guidelines have conflicting recommendations on the role of prostate artery embolization (PAE), a novel interventional radiology technique used to treat benign prostatic hyperplasia (BPH). In the absence of consensus among clinicians, patients may seek information online, where consumer-targeted content has proliferated in recent years. Our...
Article
Full-text available
IntroductionProstate cancer is a common neoplasm but conventional imaging methods such as CT and bone scan are often insensitive. A new class of PET agents have emerged to diagnose and manage prostate cancer.Methods The relevant literature on PET imaging agents for prostate cancer was reviewed.ResultsThis review shows a broad range of PET imaging a...
Article
Introduction: [111 In]In-XYIMSR-01 is a promising single-photon emission computed tomography (SPECT) imaging agent for identification of tumors that overexpress carbonic anhydrase IX. To translate [111 In]In-XYIMSR-01 to phase I trials, we performed animal toxicity and dosimetry studies, determined the maximum dose for human use, and completed the...
Article
Purpose: Erectile dysfunction significantly impacts quality of life for men undergoing radical prostatectomy (RP) for prostate cancer. Erythropoietin is a promising neurotrophic factor for neurogenic erectile dysfunction based on preclinical and retrospective data. Materials and methods: ERECT (NCT00737893) is a phase 2, double-blinded, randomiz...
Article
Purpose: Transperineal prostate biopsy offers improved sampling of the anterior prostate compared to the transrectal approach. The objective of this study was to determine if transperineal prostate biopsy is associated with an increased incidence of cancer upgrading among men on active surveillance for very low or low risk prostate cancer. Materi...
Article
Objectives: To perform an early comparative study of outcomes between SP-RALRP and standard RALRP at our institution and pooled analysis of series to date. Patients and methods: Patients with organ-confined prostate cancer undergoing SP-RALRP at a high-volume institution were identified retrospectively along with reported SP-RALRP series to date...
Article
Objective: To assess the quality and accuracy of online videos about the medical management of nephrolithiasis. Materials and methods: To evaluate trends in online interest, we first examined the frequency of worldwide YouTube searches for "kidney stones" from 2015 to 2020. We then queried YouTube with terms related to symptoms and treatment of...
Article
Full-text available
Objective To describe our technique and early results performing transperineal prostate biopsy using cognitive magnetic resonance imaging (MRI)/biplanar ultrasound fusion. Key components of this technique include use of the PrecisionPoint Transperineal Access System (Perineologic, Cumberland, MD) and simultaneous transrectal ultrasound guidance in...
Article
Objective: To evaluate perioperative complications for open and robotic-assisted RP for patients enrolled in the PREVENTER trial to determine predictors and impact on opioid consumption. Patients and methods: A prospective cohort of 500 patients undergoing open and robotic-assisted RP were followed to determine rates of complications and opioid...
Article
Background Cancer-specific survival for men with clinical stage I (CSI) seminoma approaches 100%, regardless of the management approach chosen after orchiectomy. Given the young age and high survival rate of these patients, there has been a shift toward minimizing treatment-related morbidity and cost. In this context, non–risk-adapted active survei...
Article
The role for cytoreductive nephrectomy (CN) in the treatment of metastatic renal cell carcinoma (mRCC) has evolved with advancements in systemic therapy. During the cytokine-based immunotherapy era, CN provided a clear survival benefit and was considered standard of care in management of mRCC. The development of targeted systemic therapy directed a...
Article
Full-text available
Meckel's diverticulum is the most common congenital malformation of the gastrointestinal tract. In this report, we present a patient with a Meckel's diverticulum that was incidentally discovered on prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) imaging performed for prostate cancer staging. We disc...
Article
Full-text available
OBJECTIVES/GOALS: Provider and hospital factors influence quality, but granular data is lacking to assess their impact on renal cancer surgery. The Maryland Health Service Cost Review Commission (HSCRC) is an independent state agency that promotes cost containment, access to care and accountability. Within HSCRC, we aimed to assess the impact of su...
Article
TPS5101 Background: There is no standard adjuvant systemic therapy that increases overall survival (OS) over surgery alone for non-metastatic RCC. Anti-PD-1 nivolumab (nivo) improves OS in metastatic RCC and is well tolerated. In mouse models, priming the immune system prior to surgery with anti-PD-1 results in superior OS compared to adjuvant dosi...
Article
Background Direct high-quality evidence is lacking evaluating perioperative pharmacologic prophylaxis (PP) after radical prostatectomy (RP) to prevent venous thromboembolism (VTE) leading to significant practice variation. Objective To study the impact of in-hospital PP on symptomatic VTE incidence and adverse events after RP at 30 d, with the sec...
Article
Objectives: To examine rates of Grade Group (GG) 4 downgrading at radical prostatectomy (RP) among men diagnosed with high (HR)- and very-high risk (VHR) prostate cancer (PCa) at biopsy. Methods: A pooled cohort of 1776 patients from three tertiary referral centers who underwent RP for either National Comprehensive Cancer Network (NCCN) HR (PSA...
Article
Open retroperitoneal lymph node dissection (RPLND) is the gold standard for surgical management of the retroperitoneum in patients with testicular cancer, and is associated with excellent oncologic outcomes and significant morbidity including length of stay. Minimally invasive RPLND, starting with laparoscopic retroperitoneal lymph node dissection...
Article
Purpose: Previous studies suggest that androgen deprivation therapy (ADT) promotes antitumor immunity in prostate cancer. Whether a vaccine-based approach can augment this effect remains unknown. Experimental design: Therefore, we conducted a neoadjuvant, randomized study to quantify the immunologic effects of a granulocyte-macrophage colony-sti...
Conference Paper
In recent years, immunotherapy has become one of the most exciting and promising avenues to cancer treatment. Treatment with immune checkpoint inhibitors has managed to produce long-term remission of solid tumors in many patients. However, patients who respond well to such treatment are often a minority; this is particularly the case with some canc...
Article
Among the more notable immunotherapies are checkpoint inhibitors, which prevent suppressive signaling on T cells, thereby (re)activating them to kill tumor cells. Despite remarkable treatment responses to immune checkpoint blockade, with a subset of patients achieving complete responses, a large population have little-to-no response, dictating the...
Article
610 Background: Personalized treatment for clinical T1 renal cortical masses (RCMs) should account for competing risks related to tumor and patient characteristics. Using a contemporary multi-institutional cohort, we developed treatment-specific prediction models for cancer-specific mortality (CSM), other-cause mortality (OCM), and 90-day complicat...
Article
350 Background: Ductal prostate adenocarcinoma (DAC) is an aggressive variant of prostate cancer (PC). We aimed to assess the outcomes of men with localized DAC undergoing radical prostatectomy (RP) or external beam radiotherapy (RTx) compared to acinar adenocarcinoma of the prostate (PAC) and investigate any difference between these treatment moda...
Article
TPS765 Background: There is no standard adjuvant systemic therapy that increases overall survival (OS) over surgery alone for non-metastatic RCC. Anti-PD-1 nivolumab (nivo) improves OS in metastatic RCC and is well tolerated. In mouse models, priming the immune system prior to surgery with anti-PD-1 results in superior OS compared to adjuvant dosin...
Article
Background: A proportion of men with grade group (GG) 2 intermediate risk (IR) prostate cancer are downgraded to GG1 or harbor favorable pathology (FP, defined as GG1 or GG2 with <5% Gleason pattern 4) at radical prostatectomy (RP). Prediction of downgrading or FP may help identify potential active surveillance candidates within this group that ha...
Article
Background Incidentally detected small renal masses (SRMs) may be one of several benign or malignant tumor histologies, and are heterogeneous in oncologic potential. Renal mass biopsy can be used to determine the histology of SRMs. However, this invasive approach has significant limitations. Technetium-99m sestamibi single photon emission computed...
Article
Full-text available
Schwannomas of the prostate are exceedingly rare. We present a noteworthy case of a sporadic prostatic schwannoma diagnosed in conjunction with prostatic adenocarcinoma. A 60-year-old male presented with mild lower urinary tract symptoms and a prostate specific antigen (PSA) level of 4.84 ng/mL. A transrectal ultrasound guided prostate biopsy revea...
Article
Objective: To evaluate the incidence, predictors, and survival for those small renal masses (SRM, solid mass ≤4 cm suspicious for a clinical T1a renal cell carcinoma) that disappear on imaging while undergoing active surveillance (AS). Subjects/patients and methods: The Delayed Intervention and Surveillance for SRM registry prospectively enrolle...
Article
Objectives: To evaluate the effect of a prospective opioid reduction intervention after radical prostatectomy (based on a surgery-specific guideline and education) on post-discharge opioid prescribing, use, disposal, and need for additional opioid mediation. Subjects and methods: A prospective, non-randomized, pre-post interventional trial of pa...
Article
Aims: Among renal cell carcinoma (RCC) the tumour immune microenvironment has been best characterised in clear cell RCC. In this study we investigated the expression of several immune markers, including PD-L1, FoxP3 and CD8 in primary and metastatic papillary RCC. Methods and results: Three tissue microarrays were constructed from 78 cases with...
Article
Objectives: Conditional survival (CS) represents the probability that a cancer patient will survive some additional number of years, given that the patient has already survived for a certain period of time. CS estimates, therefore, serve as better measures of survival probability compared to standard estimates as they incorporate patient survivors...
Article
Objective: To determine whether use of renal mass biopsy may be associated with a reduction in surgery for patients with small, localized renal cell carcinoma (cT1aN0M0), especially among older patients and patients with greater comorbidity burden. Methods: A total of 106,258 patients with cT1aN0M0 renal cell carcinoma from 2004-2015 were analyz...
Article
Objective: To provide a step-by-step guide for performing in-office transperineal prostate biopsy using biplanar ultrasound guidance. Patients and methods: Biopsies are performed using a freehand technique with the PrecisionPoint Transperineal Access System (Perineologic, Cumberland, MD). This disposable needle guide includes 3 components: a rai...
Article
Purpose: To provide the results of a prospective study evaluating PSMA-targeted 18F-DCFPyL PET/CT in patients with biochemical failure following radical prostatectomy for prostate cancer (PCa). Procedures: 31 patients with post-prostatectomy serum PSA levels ≥ 0.2 ng/mL and negative conventional imaging were enrolled in this study and imaged with 1...
Article
Introduction: Many patients with small renal masses (SRM) undergo surgical resection of benign and potentially indolent renal masses. We review the available literature to quantify the proportion of renal tumors that are low-risk based on clinical radiographic size, and quantify the number of low-risk masses surgically removed in the United States...
Article
Objective Complete surgical resection of metastatic sites has been shown to prolong survival in select patients with oligometastatic RCC. This treatment strategy is dependent upon the accurate characterization of a patient’s extent of disease. The objective of this study was to explore the utility of PSMA-targeted ¹⁸F-DCFPyL PET/CT in patients with...
Article
e16572 Background: Previous work has shown that the degree of expression of prostate-specific membrane antigen (PSMA) correlates with prostate cancer (PCa) grade and stage. We evaluated the additive value of a deep learning algorithm (PSMA-AI) of a PSMA-targeted small molecule SPECT/CT imaging agent ( 99m Tc-MIP-1404) to identify men with low risk...
Article
TPS4597 Background: The anti-PD-1 antibody nivo improves overall survival (OS) in metastatic RCC and is well tolerated. There is no standard adjuvant (adjuv) systemic therapy that increases OS over surgery alone for non-metastatic RCC. Priming the immune system prior to surgery with anti-PD-1 has shown an OS benefit compared to a pure adjuv approac...
Article
Patients with high-risk renal cell carcinoma (RCC) experience high rates of recurrence despite definitive surgical resection. Recent trials of adjuvant tyrosine kinase inhibitor therapy have provided conflicting efficacy results at the cost of significant adverse events. PD-1 blockade via monoclonal antibodies has emerged as an effective disease-mo...
Article
Adjuvant therapy for urothelial and renal cell carcinoma has progressed steadily over the past 30 yr. Level 1 evidence supports a role for both neoadjuvant and adjuvant cisplatin-based chemotherapy for muscle-invasive urothelial carcinoma of the bladder. Recent evidence has also confirmed a benefit from adjuvant therapy in high-grade upper tract ur...
Article
Background: Localized prostate cancer rarely undergoes a shift in metabolism towards aerobic glycolysis, a process known as the Warburg Effect. Because of this, positron emission tomography (PET)/CT imaging using 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) is uncommonly used to evaluate patients with early-stage prostate cancer. However, men undergoi...
Article
TPS684 Background: The anti-PD-1 antibody nivo improves overall survival in metastatic RCC and is well tolerated. There is no standard adjuvant systemic therapy that increases overall survival (OS) over surgery alone for non-metastatic RCC. Priming the immune system prior to surgery with anti-PD-1 has shown an OS benefit compared to a pure adjuvant...