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Dive into the research topics where Stanley B. Malkowicz is active.

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Featured researches published by Stanley B. Malkowicz.


Journal of Vascular and Interventional Radiology | 2012

Impact on renal function of percutaneous thermal ablation of renal masses in patients with preexisting chronic kidney disease.

Eric Wehrenberg-Klee; Timothy W.I. Clark; Stanley B. Malkowicz; Michael C. Soulen; Alan J. Wein; Jeffrey I. Mondschein; Keith N. Van Arsdalen; Thomas J. Guzzo; S. William Stavropoulos

PURPOSE To examine the effect of percutaneous thermal ablation of renal masses on renal function among patients with baseline chronic kidney disease (CKD). MATERIALS AND METHODS Patients with baseline CKD (initial glomerular filtration rate [GFR] < 60 mL/min/1.73 m(2)) who underwent percutaneous cryoablation or radiofrequency (RF) ablation of renal masses were reviewed. RESULTS A total of 48 patients with a GRF of 60 mL/min/1.73 m(2) or lower were treated with renal cryoablation or RF ablation and had follow-up GFR measurement 1 month afterward. Mean patient age was 73 years (range, 47-89 y). Cryoablation was performed in 22 patients and RF ablation was performed in 26. Mean tumor diameter was 3.4 cm (range, 0.9-10.2 cm). Mean overall GFRs were 39.8 mL/min/1.73 m(2) at baseline and 39.7 mL/min/1.73 m(2) at 1 month after ablation (P = .85). A total of 38 patients had 1-year follow-up GFR measurement (cryoablation, n = 18; RF ablation, n = 20), and their mean GFR was 40.9 mL/min/1.73 m(2) ± 11.4 (SD), compared with a preablation GFR of 41.2 mL/min/1.73 m(2)(P = .79). In the cryoablation group, mean GFRs at 1 month and 1 year were 41.4 mL/min/1.73 m(2) and 44.4 mL/min/1.73 m(2), compared with respective baseline GFRs of 41.1 mL/min/1.73 m(2) and 42.1 mL/min/1.73 m(2) (P = .75 and P = .19, respectively). In the RF ablation group, mean GFRs at 1 month and 1 year were 38.2 mL/min/1.73 m(2) and 37.8 mL/min/1.73 m(2), compared with respective baseline GFRs of 38.7 mL/min/1.73 m(2) and 40.4 mL/min/1.73 m(2) (P = .58 and P = .09, respectively). CONCLUSIONS Independent of ablation modality, percutaneous renal mass ablation does not appear to affect renal function among patients with CKD.


Modern Pathology | 2005

Impact of the 1998 World Health Organization/International Society of Urological Pathology classification system for urothelial neoplasms of the kidney.

Elizabeth M. Genega; Malathy Kapali; Marta Torres-Quinones; William C. Huang; Jill S. Knauss; Li-Ping Wang; Puthiyaveettil N. Raghunath; Christopher Kozlowski; Stanley B. Malkowicz; John E. Tomaszewski

The classification of urothelial neoplasms of the kidney traditionally has been similar to that of urinary bladder tumors. Several years ago, the classification of papillary urothelial neoplasms was revised. The current study focuses on the application of the 1998 World Health Organization (WHO)/International Society of Urological Pathology classification system to 102 renal pelvic urothelial neoplasms and compares it to the 1973 WHO classification scheme. In this study, all tumors were classified as urothelial carcinomas, and the majority (85%) were papillary. Most patients with papillary tumors presented with ‘superficial’ disease (≤pT1). With the 1998 system, most papillary carcinomas were high grade, and were more often invasive as compared to low-grade tumors. Only 34% were low-grade papillary tumors and, of these, most (93%) were noninvasive. With the 1973 system, most papillary tumors were grade 2 or 3, with invasion more common in grade 3 tumors. By 1973 criteria, grade 2 tumors were a heterogeneous group; with 1998 criteria, nearly one-half were high grade and the other half low grade. The grade of papillary urothelial carcinomas with both the 1973 and 1998 grading methods was associated with stage (P=0.001). Our study reveals that papillomas and papillary urothelial neoplasms of low malignant potential are uncommon tumors in the kidney. Renal pelvic papillary urothelial neoplasms are most often carcinomas and are more commonly high grade than low grade. Although both the 1973 and 1998 systems showed a significant association with tumor stage, grade 2 papillary carcinomas are a heterogeneous group by 1973 criteria. The 1998 system provides useful information in that it more clearly defines a papillary tumors grade and selects for a group of tumors, namely low-grade papillary urothelial carcinomas, for which a low likelihood of invasion can be predicted.


Health Services Research | 2012

Comparison of Distribution‐ and Anchor‐Based Approaches to Infer Changes in Health‐Related Quality of Life of Prostate Cancer Survivors

Ravishankar Jayadevappa; Stanley B. Malkowicz; Marsha N. Wittink; Alan J. Wein; Sumedha Chhatre

OBJECTIVE To determine the minimal important difference (MID) in generic and prostate-specific health-related quality of life (HRQoL) using distribution- and anchor-based methods. STUDY DESIGN AND SETTING Prospective cohort study of 602 newly diagnosed prostate cancer patients recruited from an urban academic hospital and a Veterans Administration hospital. Participants completed generic (SF-36) and prostate-specific HRQoL surveys at baseline and at 3, 6, 12, and 24 months posttreatment. Anchor-based and distribution-based methods were used to develop MID estimates. We compared the proportion of participants returning to baseline based on MID estimates from the two methods. RESULTS MID estimates derived from combining distribution- and anchor-based methods for the SF-36 subscales are physical function = 7, role physical = 14, role emotional = 12, vitality = 9, mental health = 6, social function = 9, bodily pain = 9, and general health = 8; and for the prostate-specific scales are urinary function = 8, bowel function = 7, sexual function = 8, urinary bother = 9, bowel bother = 8, and sexual bother = 11. Proportions of participants returning to baseline values corresponding to MID estimates from the two methods were comparable. CONCLUSIONS This is the first study to assess the MID for generic and prostate-specific HRQoL using anchor-based and distribution-based methods. Although variation exists in the MID estimates derived from these two methods, the recovery patterns corresponding to these estimates were comparable.


Journal of Vascular and Interventional Radiology | 2010

Embolization of Giant Renal Angiomyolipomas: Technique and Results

Vivian L. Bishay; Peter B. Crino; Alan J. Wein; Stanley B. Malkowicz; Scott O. Trerotola; Michael C. Soulen; S. William Stavropoulos

PURPOSE To evaluate the efficacy and safety of prophylactic embolization of angiomyolipomas (AMLs) larger than 10 cm. MATERIALS AND METHODS Sixteen patients (mean age, 41.2 years; 14 women and two men) underwent embolization for 23 AMLs larger than 10 cm. All lesions were embolized by using microcatheters with ethanol and ethiodized oil mixed to a ratio of 7(ethanol) to 3(ethiodized oil). Data collected included pre- and posttreatment AML size, creatinine level, technical success, volume of embolic material used, clinical success, and complications. RESULTS The mean AML size before treatment was 15 cm (range, 10-25 cm). Ten of the 16 patients (62%) had all their AMLs treated in one session, whereas six (38%) required multiple sessions. A mean volume of 8.6 mL of the ethanol-ethiodized oil mixture (range, 2-20 mL) was administered per lesion. Patients were followed up for a mean of 29 months (range, 1-80 months). No patient had an increase of 0.2 mg/dL (17.7 mumol/L) or greater in mean serum creatinine level during the follow-up period. Two of the 16 patients (12%) required repeat embolization due to AML regrowth (n = 1) or reperfusion (n = 1) seen at surveillance imaging. One of the 16 patients (6.2%) had an AML hemorrhage 59 months after AML embolization. CONCLUSIONS Embolization of giant renal AMLs to decrease the risk of bleeding can be done safely without loss of renal function. Although recurrence was infrequent, additional treatment may be necessary and giant renal AMLs should be followed up with serial imaging studies.


Journal of Vascular and Interventional Radiology | 2016

Percutaneous Renal Cryoablation: Short-Axis Ice-Ball Margin as a Predictor of Outcome.

Benjamin H. Ge; Thomas J. Guzzo; G. Nadolski; Michael C. Soulen; Timothy W.I. Clark; Stanley B. Malkowicz; Alan J. Wein; S. Hunt; S. William Stavropoulos

PURPOSE To determine if CT characteristics of intraprocedural ice balls correlate with outcomes after cryoablation. MATERIALS AND METHODS A retrospective review was performed on 63 consecutive patients treated with renal cryoablation. Preprocedural and intraprocedural images were used to identify the size and location of renal tumors and ice balls as well as the tumor coverage and ice-ball margins. Review of follow-up imaging (1 mo and then 3-6-mo intervals) distinguished successful ablations from cases of residual tumor. RESULTS Patients who underwent successful ablation (n = 50; 79%) had a mean tumor diameter of 2.5 cm (range, 0.9-4.3 cm) and mean ice-ball margin of 0.4 cm (range, 0.2-1.2 cm). Patients with residual tumor (n = 13; 21%) had a mean tumor diameter of 3.8 cm (range, 1.8-4.5 cm) and mean ice-ball margin of -0.4 cm (range, -0.9 to 0.4 cm). Residual and undertreated tumors were larger and had smaller ice-ball margins than successfully treated tumors (P < .01). Ice-ball diameters were significantly smaller after image reformatting (P < .01). Ice-ball margins of 0.15 cm had 90% sensitivity, 92% specificity, and 98% positive predictive value for successful ablation. Success was independent of tumor location or number of cryoprobes. CONCLUSIONS Ice-ball margin and real-time intraprocedural reformatting could be helpful in predicting renal cryoablation outcomes. Although a 0.5-cm margin is preferred, a well-centered ice ball with a short-axis margin greater than 0.15 cm strongly correlated with successful ablation.


Health Policy | 2011

Association between ethnicity and prostate cancer outcomes across hospital and surgeon volume groups

Ravishankar Jayadevappa; Sumedha Chhatre; Jerry C. Johnson; Stanley B. Malkowicz

OBJECTIVE We analyzed the association between ethnicity and outcomes among prostate cancer patients across hospital and surgeon volume groups. METHODS In this retrospective cohort study using SEER-Medicare databases for the period between 1995 and 2003, prostate cancer cases were identified and retrospectively followed for one year pre- and up to eight years post-diagnosis. Based on volume, hospitals and surgeons were divided into three groups each. For each group, we fitted separate models to analyze the association between ethnicity and outcomes such as complications, eight-year mortality and cost, adjusting for covariates. Poisson (zero inflation), generalized linear model (log-link), and Cox regression models were used. RESULTS African American ethnicity was associated with 30-day complications among medium volume hospital group. African American patients receiving care at medium volume hospitals and from medium volume surgeons had higher costs. Hispanic patients receiving care at low and medium volume hospitals had lower cost compared to white patients. Hispanic patients receiving care from a high-volume surgeon experienced increased hazard of long-term mortality. CONCLUSIONS Association between ethnicity and outcomes varies across hospital and surgeon volume groups. Thus, volume based policy measures may need further exploration for understanding the interaction between structure, process, volume and outcomes.


Medicine | 2017

Comparative effectiveness of prostate cancer treatments for patient-centered outcomes: A systematic review and meta-analysis (PRISMA Compliant)

Ravishankar Jayadevappa; Sumedha Chhatre; Yu Ning Wong; Marsha N. Wittink; Ratna Cook; Knashawn H. Morales; Neha Vapiwala; Diane K. Newman; Thomas J. Guzzo; Alan J. Wein; Stanley B. Malkowicz; David I. Lee; Jerome Sanford Schwartz; Joseph J. Gallo

Background: In the context of prostate cancer (PCa) characterized by the multiple alternative treatment strategies, comparative effectiveness analysis is essential for informed decision-making. We analyzed the comparative effectiveness of PCa treatments through systematic review and meta-analysis with a focus on outcomes that matter most to newly diagnosed localized PCa patients. Methods: We performed a systematic review of literature published in English from 1995 to October 2016. A search strategy was employed using terms “prostate cancer,” “localized,” “outcomes,” “mortality,” “health related quality of life,” and “complications” to identify relevant randomized controlled trials (RCTs), prospective, and retrospective studies. For observational studies, only those adjusting for selection bias using propensity-score or instrumental-variables approaches were included. Multivariable adjusted hazard ratio was used to assess all-cause and disease-specific mortality. Funnel plots were used to assess the level of bias. Results: Our search strategy yielded 58 articles, of which 29 were RCTs, 6 were prospective studies, and 23 were retrospective studies. The studies provided moderate data for the patient-centered outcome of mortality. Radical prostatectomy demonstrated mortality benefit compared to watchful waiting (all-cause HR = 0.63 CI = 0.45, 0.87; disease-specific HR = 0.48 CI = 0.40, 0.58), and radiation therapy (all-cause HR = 0.65 CI = 0.57, 0.74; disease-specific HR = 0.51 CI = 0.40, 0.65). However, we had minimal comparative information about tradeoffs between and within treatment for other patient-centered outcomes in the short and long-term. Conclusion: Lack of patient-centered outcomes in comparative effectiveness research in localized PCa is a major hurdle to informed and shared decision-making. More rigorous studies that can integrate patient-centered and intermediate outcomes in addition to mortality are needed.


Medicine | 2015

Understanding the Racial and Ethnic Differences in Cost and Mortality Among Advanced Stage Prostate Cancer Patients (STROBE).

Sumedha Chhatre; Stanley B. Malkowicz; J. Sanford Schwartz; Ravishankar Jayadevappa

AbstractThe aims of the study were to understand the racial/ethnic differences in cost of care and mortality in Medicare elderly with advanced stage prostate cancer.This retrospective, observational study used SEER-Medicare data. Cohort consisted of 10,509 men aged 66 or older and diagnosed with advanced-stage prostate cancer between 2001and 2004. The cohort was followed retrospectively up to 2009. Racial/ethnic variation in cost was analyzed using 2 part-models and quantile regression. Step-wise GLM log-link and Cox regression was used to study the association between race/ethnicity and cost and mortality. Propensity score approach was used to minimize selection bias.Pattern of cost and mortality varies between racial/ethnic groups. Compared with other racial/ethnic groups, non-Hispanic white patients had higher unadjusted costs in treatment and follow-up phases. Quintile regression results indicated that in treatment phase, Hispanics had higher costs in the 95th quantile and non-Hispanic blacks had lower cost in the 95th quantile, compared with non-Hispanic white men. In terminal phase non-Hispanic blacks and Hispanics had higher cost. After controlling for treatment, all-cause and prostate cancer-specific mortality was not significant for non-Hispanic black men, compared with non-Hispanic white men. However, for Asians, mortality remained significantly lower compared with non-Hispanic white men.In conclusion, relationship between race/ethnicity, cost of care, and mortality is intricate. For non-Hispanic black men, disparity in mortality can be attributed to treatment differences. To reduce racial/ethnic disparities in prostate cancer care and outcomes, tailored policies to address underuse, overuse, and misuse of treatment and health services are necessary.


Journal of Clinical Oncology | 2005

Pilot trial of adjuvant paclitaxel (T) and estramustine phosphate (EMP) for high-risk prostate cancer patients after radical prostatectomy (RP)

G. M. Lubiniecki; Stanley B. Malkowicz; M. Hendricks; L. Bearn-Miranda; K. van Arsdalen; Alan J. Wein; David J. Vaughn

4775 Background: A previous study from our center demonstrated that preoperative prostate specific antigen (PSA) and prostatectomy pathology can identify patients with a high risk of 2-year PSA failure (D’Amico, et al., J. Urology, 1998). We hypothesize that chemotherapy active in hormone-refractory prostate cancer could decrease this risk. We are performing a pilot trial of adjuvant T plus EMP in patients with a 2-year PSA failure risk of ≥50%. Methods: Men within 12 weeks of RP with a ≥50% predicted risk of 2-year PSA failure, as predicted by the above study, received T 90mg/m2 days 2, 9, and 16 every 28 days, and EMP 420mg orally days 1–3, 8–10, and 15–17 every 28 days. Four cycles were given. Men were followed with serial PSA examinations every three months after completing therapy. Results: As of December 2004, 15 patients have been accrued. Median age: 60 (51–69). Median predicted 2-year PSA failure risk: 70 (52–99). 13 patients have completed therapy with a median follow-up of 12 (1.5–31) months. P...


The Journal of Urology | 2004

256: The Significance of Frozen Section Ureteral Abnormalities at Time of Cystectomy

William C. Huang; Ricardo Sanchez-Ortiz; Elizabeth M. Genega; Stanley B. Malkowicz

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Sumedha Chhatre

University of Pennsylvania

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Alan J. Wein

University of Pennsylvania

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David S. Metzger

University of Pennsylvania

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Thomas J. Guzzo

University of Pennsylvania

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George E. Woody

University of Pennsylvania

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Michael C. Soulen

University of Pennsylvania

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Elizabeth M. Genega

Beth Israel Deaconess Medical Center

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