Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Alon Z. Weizer is active.

Publication


Featured researches published by Alon Z. Weizer.


Cancer | 2009

Outcomes of radical nephroureterectomy: A series from the Upper Tract Urothelial Carcinoma Collaboration

Vitaly Margulis; Shahrokh F. Shariat; Surena F. Matin; Ashish M. Kamat; Richard Zigeuner; Eiji Kikuchi; Yair Lotan; Alon Z. Weizer; Jay D. Raman; Christopher G. Wood

The literature on upper tract urothelial carcinoma (UTUC) has been limited to small, single center studies. A large series of patients treated with radical nephroureterectomy for UTUC were studied, and variables associated with poor prognosis were identified.


The Journal of Urology | 2009

Adjuvant chemotherapy for high risk upper tract urothelial carcinoma: results from the Upper Tract Urothelial Carcinoma Collaboration.

Nicholas J. Hellenthal; Shahrokh F. Shariat; Vitaly Margulis; Pierre I. Karakiewicz; Marco Roscigno; Christian Bolenz; Mesut Remzi; Alon Z. Weizer; Richard Zigeuner; K. Bensalah; Casey K. Ng; Jay D. Raman; Eiji Kikuchi; Francesco Montorsi; Mototsugu Oya; Christopher G. Wood; Mario Fernandez; Christopher P. Evans; Theresa M. Koppie

PURPOSE There is relatively little literature on adjuvant chemotherapy after radical nephroureterectomy in patients with upper tract urothelial carcinoma. We determined the incidence of adjuvant chemotherapy in high risk patients and the ensuing effect on overall and cancer specific survival. MATERIALS AND METHODS Using an international collaborative database we identified 1,390 patients who underwent nephroureterectomy for nonmetastatic upper tract urothelial carcinoma between 1992 and 2006. Of these cases 542 (39%) were classified as high risk (pT3N0, pT4N0 and/or lymph node positive). These patients were divided into 2 groups, including those who did and did not receive adjuvant chemotherapy, and stratified by gender, age group, performance status, and tumor grade and stage. Cox proportional hazard modeling and Kaplan-Meier analysis were used to determine overall and cancer specific survival in the cohorts. RESULTS Of high risk patients 121 (22%) received adjuvant chemotherapy. Adjuvant chemotherapy was more commonly administered in the context of increased tumor grade and stage (p <0.001). Median survival in the entire cohort was 24 months (range 0 to 231). There was no significant difference in overall or cancer specific survival between patients who did and did not receive adjuvant chemotherapy. However, age, performance status, and tumor grade and stage were significant predictors of overall and cancer specific survival. CONCLUSIONS Adjuvant chemotherapy is infrequently used to treat high risk upper tract urothelial carcinoma after nephroureterectomy. Despite this finding it appears that adjuvant chemotherapy confers minimal impact on overall or cancer specific survival in this group.


Journal of Immunology | 2003

Injection of Immature Dendritic Cells into Adjuvant-Treated Skin Obviates the Need for Ex Vivo Maturation

Smita K. Nair; Catherine McLaughlin; Alon Z. Weizer; Zhen Su; David Boczkowski; Jens Dannull; Johannes Vieweg; Eli Gilboa

A key and limiting step in the process of generating human monocyte-derived dendritic cells (DC) for clinical applications is maturation. In the setting of immunotherapy, DC are matured ex vivo by culturing them with various agents that mimic the conditions encountered at a site of inflammation. This study examined whether the ex vivo DC maturation step could be replaced by maturing DC in situ by injecting immature DC into sites pre-exposed to agents that induce a microenvironment conducive to in situ maturation of the injected DC. The hypothesis was that recapitulation of the physiological conditions occurring during pathogen infection would lead to optimal conditions for DC maturation, migration, and function. Murine immature DC injected into adjuvant (Adjuprime, poly-arginine, or Imiquimod)-pretreated skin exhibited lymph node migratory capacity comparable to and immunostimulatory capacity equal to or exceeding that of ex vivo matured DC. Acquisition of migratory capacity did not always correlate with enhanced immunostimulatory capacity. Immunostimulatory capacity was not enhanced when mature DC were injected into adjuvant-pretreated sites and remained below that seen with immature DC matured in situ. Immature DC injected into adjuvant-pretreated sites were more effective than mature DC in stimulating antitumor immunity in mice. 111Indium-labeled human monocyte-derived immature DC injected into adjuvant (Imiquimod)-pretreated sites in cancer patients acquired lymph node migratory capacity comparable to ex vivo matured DC. This study shows that in situ maturation offers a simpler and potentially superior method to generate potent immunostimulatory DC for clinical immunotherapy.


European Urology | 2009

Comparison of Oncologic Outcomes for Open and Laparoscopic Nephroureterectomy: A Multi-Institutional Analysis of 1249 Cases

Umberto Capitanio; Shahrokh F. Shariat; Hendrik Isbarn; Alon Z. Weizer; Mesut Remzi; Marco Roscigno; Eiji Kikuchi; Jay D. Raman; Christian Bolenz; K. Bensalah; Theresa M. Koppie; Wassim Kassouf; Mario Fernandez; Philipp Ströbel; Jeffrey Wheat; Richard Zigeuner; Cord Langner; Matthias Waldert; Mototsugu Oya; Charles C. Guo; Casey Ng; Francesco Montorsi; Christopher G. Wood; Vitaly Margulis; Pierre I. Karakiewicz

BACKGROUND Data regarding the oncologic efficacy of laparoscopic nephroureterectomy (LNU) compared to open nephroureterectomy (ONU) are scarce. OBJECTIVE We compared recurrence and cause-specific mortality rates of ONU and LNU. DESIGN, SETTING, AND PARTICIPANTS Thirteen centers from three continents contributed data on 1249 patients with nonmetastatic upper tract urothelial carcinoma (UTUC). MEASUREMENTS Univariable and multivariable survival models tested the effect of procedure type (ONU [n=979] vs LNU [n=270]) on cancer recurrence and cancer-specific mortality. Covariables consisted of institution, age, Eastern Cooperative Oncology Group (ECOG) performance status score, pT stage, pN stage, tumor grade, lymphovascular invasion, tumor location, concomitant carcinoma in situ, ureteral cuff management, previous urothelial bladder cancer, and previous endoscopic treatment. RESULTS AND LIMITATIONS Median follow-up for censored cases was 49 mo (mean: 62). Relative to ONU, LNU patients had more favorable pathologic stages (pT0/Ta/Tis: 38.1% vs 20.8%, p<0.001) and less lymphovascular invasion (14.8% vs 21.3%, p=0.02) and less frequently had tumors located in the ureter (64.5 vs 71.1%, p=0.04). In univariable recurrence and cancer-specific mortality models, ONU was associated with higher cancer recurrence and mortality rates compared to LNU (hazard ratio [HR]: 2.1 [p<0.001] and 2.0 [p=0.008], respectively). After adjustment for all covariates, ONU and LNU had no residual effect on cancer recurrence and mortality (p=0.1 for both). CONCLUSIONS Short-term oncologic data on LNU are comparable to ONU. Since LNU was selectively performed in favorable-risk patients, we cannot state with certainty that ONU and LNU have the same oncologic efficacy in poor-risk patients. Long-term follow-up data and morbidity data are necessary before LNU can be considered as the standard of care in patients with muscle-invasive or high-grade UTUC.


The Journal of Urology | 2009

Impact of Lymph Node Dissection on Cancer Specific Survival in Patients With Upper Tract Urothelial Carcinoma Treated With Radical Nephroureterectomy

Marco Roscigno; Shahrokh F. Shariat; Vitaly Margulis; Pierre I. Karakiewicz; Mesut Remzi; Eiji Kikuchi; Cord Langner; Yair Lotan; Alon Z. Weizer; K. Bensalah; Jay D. Raman; Christian Bolenz; Charles C. Guo; Christopher G. Wood; Richard Zigeuner; Jeffrey Wheat; Wareef Kabbani; Theresa M. Koppie; Casey K. Ng; Nazareno Suardi; Roberto Bertini; Mario Fernandez; Shuji Mikami; Masaru Isida; Maurice Stephan Michel; Francesco Montorsi

PURPOSE We examined the impact of lymphadenectomy on the clinical outcomes of patients with upper tract urothelial cancer treated with radical nephroureterectomy. MATERIALS AND METHODS Data were collected on 1,130 consecutive patients with pT1-4 upper tract urothelial cancer treated with radical nephroureterectomy at 13 centers worldwide. Patients were grouped according to nodal status (pN0 vs pNx vs pN+). The choice to perform lymphadenectomy was determined by the treating surgeon. All pathology slides were reevaluated by dedicated genitourinary pathologists. Univariable and multivariable Cox regression models measured the association of nodal status (pN0 vs pNx vs pN+) with cancer specific survival. RESULTS Overall 412 patients (36.5%) had pN0 disease, 578 had pNx disease (51.1%) and 140 had pN+ disease (12.4%). The 5-year cancer specific survival estimate was lower in patients with pN+ compared to those with pNx disease (35% vs 69%, p <0.001), which in turn was lower than that in those with pN0 disease (69% vs 77%, p = 0.024). In the subgroup of patients with pT1 disease (345) cancer specific survival rates were not different in those with pN0 and pNx. In pT2-4 cases (813) cancer specific survival estimates were lowest in pN+, intermediate in pNx and highest in pN0 (33% vs 58% vs 70%, p = 0.017). When adjusted for the effects of standard clinicopathological features pN+ was an independent predictor of cancer specific survival (p <0.001). pNx was significantly associated with worse prognosis than pN0 in pT2-4 upper tract urothelial cancer only. CONCLUSIONS Nodal status is a significant predictor of cancer specific survival in upper tract urothelial cancer. pNx is significantly associated with a worse prognosis than pN0 in pT2-4 tumors. Patients expected to have pT2-4 disease should undergo lymphadenectomy to improve staging and thereby help guide decision making regarding adjuvant chemotherapy.


Cancer | 2007

Measuring Health-Related Quality of Life Outcomes in Bladder Cancer Patients Using the Bladder Cancer Index (BCI)

Scott M. Gilbert; David P. Wood; Rodney L. Dunn; Alon Z. Weizer; Cheryl T. Lee; James E. Montie; John T. Wei

Health‐related quality of life (HRQOL) has not been adequately measured in bladder cancer. A recently developed reliable and disease‐specific quality of life instrument (Bladder Cancer Index, BCI) was used to measure urinary, sexual, and bowel function and bother domains in patients with bladder cancer managed with several different interventions, including cystectomy and endoscopic‐based procedures.


European Urology | 2013

Complications After Robot-assisted Radical Cystectomy: Results from the International Robotic Cystectomy Consortium

Raza Johar; Matthew H. Hayn; Andrew P. Stegemann; Kamran Ahmed; Piyush K. Agarwal; M. Derya Balbay; Ashok K. Hemal; Adam S. Kibel; Fred Muhletaler; Kenneth G. Nepple; John Pattaras; James O. Peabody; Joan Palou Redorta; Koon Ho Rha; Lee Richstone; Matthias Saar; Francis Schanne; Douglas S. Scherr; S. Siemer; Michael Stökle; Alon Z. Weizer; Peter Wiklund; Timothy Wilson; Michael Woods; Bertrum Yuh; Khurshid A. Guru

BACKGROUND Complication reporting is highly variable and nonstandardized. Therefore, it is imperative to determine the surgical outcomes of major oncologic procedures. OBJECTIVE To describe the complications after robot-assisted radical cystectomy (RARC) using a standardized and validated reporting methodology. DESIGN, SETTING, AND PARTICIPANTS Using the International Robotic Cystectomy Consortium (IRCC) database, we identified 939 patients who underwent RARC, had available complication data, and had at least 90 d of follow-up. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Complications were analyzed and graded according to the Memorial Sloan-Kettering Cancer Center (MSKCC) system and were defined and stratified by organ system. Secondary outcomes included identification of preoperative and intraoperative variables predicting complications. Logistic regression models were used to define predictors of complications and readmission. RESULTS AND LIMITATIONS Forty-one percent (n=387) and 48% (n=448) of patients experienced a complication within 30 and 90 d of surgery, respectively. The highest grade of complication was grade 0 in 52%, grade 1-2 in 29%, and grade 3-5 in 19% patients. Gastrointestinal, infectious, and genitourinary complications were most common (27%, 23%, and 17%, respectively). On multivariable analysis, increasing age group, neoadjuvant chemotherapy, and receipt of blood transfusion were independent predictors of any and high-grade complications, respectively. Thirty and 90-d mortality was 1.3% and 4.2%, respectively. As a multi-institutional database, a disparity in patient selection, operating standards, postoperative management, and reporting of complications can be considered a major limitation of the study. CONCLUSIONS Surgical morbidity after RARC is significant when reported using a standardized reporting methodology. The majority of complications are low grade. Strict reporting of complications is necessary to advocate for radical cystectomy (RC) and helps in patient counseling.


European Urology | 2010

Impact of Tumor Location on Prognosis for Patients with Upper Tract Urothelial Carcinoma Managed by Radical Nephroureterectomy

Jay D. Raman; Casey K. Ng; Douglas S. Scherr; Vitaly Margulis; Yair Lotan; K. Bensalah; Jean Jacques Patard; Eiji Kikuchi; Francesco Montorsi; Richard Zigeuner; Alon Z. Weizer; Christian Bolenz; Theresa M. Koppie; Hendrik Isbarn; Claudio Jeldres; Wareef Kabbani; Mesut Remzi; Mathias Waldert; Christopher G. Wood; Marco Roscigno; Mototsuga Oya; Cord Langner; J. Stuart Wolf; Philipp Ströbel; Mario Fernandez; Pierre Karakiewcz; Shahrokh F. Shariat

BACKGROUND There is a lack of consensus regarding the prognostic significance of ureteral versus renal pelvic upper tract urothelial carcinoma (UTUC). OBJECTIVE To investigate the association of tumor location on outcomes for UTUC in an international cohort of patients managed by radical nephroureterectomy (RNU). DESIGN, SETTING, AND PARTICIPANTS A retrospective review of institutional databases from 10 institutions worldwide identified patients with UTUC. INTERVENTION The 1249 patients in the study underwent RNU with ipsilateral bladder cuff resection between 1987 and 2007. MEASUREMENTS Data accrued included age, gender, race, surgical approach (open vs laparoscopic), tumor pathology (stage, grade, lymph node status), tumor location, use of perioperative chemotherapy, prior endoscopic therapy, urothelial carcinoma recurrence, and mortality from urothelial carcinoma. Tumor location was divided into two groups (renal pelvis and ureter) based on the location of the dominant tumor. RESULTS AND LIMITATIONS The 5-yr recurrence-free and cancer-specific survival estimates for this cohort were 75% and 78%, respectively. On multivariate analysis, only pathologic tumor (pT) classification (p<0.001), grade (p<0.02), and lymph node status (p<0.001) were associated with disease recurrence and cancer-specific survival. When adjusting for these variables, there was no difference in the probability of disease recurrence (hazard ratio [HR]: 1.22; p=0.133) or cancer death (HR: 1.23; p=0.25) between ureteral and renal pelvic tumors. Adding tumor location to a base prognostic model for disease recurrence and cancer death that included pT stage, tumor grade, and lymph node status only improved the predictive accuracy of this model by 0.1%. This study is limited by biases associated with its retrospective design. CONCLUSIONS There is no difference in outcomes between patients with renal pelvic tumors and with ureteral tumors following nephroureterectomy. These data support the current TNM staging system, whereby renal pelvic and ureteral carcinomas are classified as one integral group of tumors.


The Journal of Urology | 2010

Preoperative multivariable prognostic model for prediction of nonorgan confined urothelial carcinoma of the upper urinary tract

Vitaly Margulis; Ramy F. Youssef; Pierre I. Karakiewicz; Yair Lotan; Christopher G. Wood; Richard Zigeuner; Eiji Kikuchi; Alon Z. Weizer; Jay D. Raman; Mesut Remzi; Marco Roscigno; Francesco Montorsi; Christian Bolenz; Wassim Kassouf; Shahrokh F. Shariat

PURPOSE We created a prognostic tool for the accurate preoperative prediction of nonorgan confined upper tract urothelial carcinoma. MATERIALS AND METHODS A computerized data bank containing comprehensive information on 1,453 patients who underwent radical nephroureterectomy at 13 academic institutions was generated and continuously updated. This study comprised a subset of 659 patients in whom all appropriate preoperative prognostic variables (age, gender, race, symptoms, Eastern Cooperative Oncology Group performance status, primary tumor location, tumor architecture, tumor grade and history of previous bladder cancer) were available for statistical analysis. A multivariable logistic regression model containing relevant clinicopathological variables addressed the prediction of nonorgan confined stage disease (T3-4 and/or N+) at radical nephroureterectomy. A backward step-down selection process was applied to achieve the most informative and parsimonious model. Internal validation was performed using 200 bootstrap resamples. RESULTS Pathological nonorgan confined urothelial carcinoma was found in 40% of patients. Grade, architecture and location of the tumor were independently associated with nonorgan confined disease. A nomogram including these 3 variables achieved 76.6% accuracy in predicting nonorgan confined upper tract urothelial cancer. CONCLUSIONS We developed a simple and accurate prognostic tool for the prediction of locally advanced upper tract urothelial cancer. This preoperative prediction model can be used for designing clinical trials, selecting patients for preoperative systemic therapy and guiding the extent of concomitant lymph node dissection at nephroureterectomy.


The Journal of Urology | 2012

Accuracy of Determining Small Renal Mass Management with Risk Stratified Biopsies: Confirmation by Final Pathology

Schuyler Halverson; Lakshmi P. Kunju; Ritu Bhalla; Adam J. Gadzinski; Megan A. Alderman; David C. Miller; Jeffrey S. Montgomery; Alon Z. Weizer; Angela Wu; Khaled S. Hafez; J. Stuart Wolf

PURPOSE We assess the accuracy of a biopsy directed treatment algorithm in correctly assigning active surveillance vs treatment in patients with small renal masses by comparing biopsy results with final surgical pathology. MATERIALS AND METHODS From 1999 to 2011, 151 patients with small renal masses 4 cm or smaller underwent biopsy and subsequent surgical excision. Biopsy revealed cell type and grade in 133 patients, allowing the hypothetical assignment of surveillance vs treatment using an algorithm incorporating small renal mass size and histological risk group. We compared the biopsy directed management recommendation with the ideal management as defined by final surgical pathology. RESULTS Biopsy called for surveillance of 36 small renal masses and treatment of 97 small renal masses. Final pathology showed 11 patients initially assigned to surveillance should have been assigned to treatment (8.3% of all patients, 31% of those recommended for surveillance), whereas no patients moved from treatment to surveillance. Agreement between biopsy and final pathology was 92%. Using management based on final pathology as the reference standard, biopsy had a negative predictive value of 0.69 and positive predictive value 1.0 for determining management. Of the 11 misclassified cases, 7 had a biopsy indicating grade 1 clear cell renal cancer which was upgraded to grade 2 (5) or grade 3 (2). After modifying the histological risk group assignment to account for undergrading of clear cell renal cancer, agreement improved to 97%, with a negative predictive value of 0.86 and a positive predictive value of 1.0. CONCLUSIONS Our results suggest that compared to final pathology, biopsy of small renal masses accurately informs an algorithm incorporating size and histological risk group that directs the management of small renal masses.

Collaboration


Dive into the Alon Z. Weizer's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Shahrokh F. Shariat

Medical University of Vienna

View shared research outputs
Top Co-Authors

Avatar

Vitaly Margulis

University of Texas Southwestern Medical Center

View shared research outputs
Top Co-Authors

Avatar

Yair Lotan

University of Texas Southwestern Medical Center

View shared research outputs
Top Co-Authors

Avatar

Jay D. Raman

Penn State Milton S. Hershey Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Christopher G. Wood

University of Texas MD Anderson Cancer Center

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge