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Dive into the research topics where Mark E. Snyder is active.

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Featured researches published by Mark E. Snyder.


Lancet Oncology | 2006

Chronic kidney disease after nephrectomy in patients with renal cortical tumours: a retrospective cohort study

William C. Huang; Andrew S. Levey; Angel M. Serio; Mark E. Snyder; Andrew J. Vickers; Ganesh V. Raj; Peter T. Scardino; Paul Russo

BACKGROUND Chronic kidney disease is a graded and independent risk factor for substantial comorbidity and death. We aimed to examine new onset of chronic kidney disease in patients with small, renal cortical tumours undergoing radical or partial nephrectomy. METHODS We did a retrospective cohort study of 662 patients with a normal concentration of serum creatinine and two healthy kidneys undergoing elective partial or radical nephrectomy for a solitary, renal cortical tumour (</=4 cm) between 1989 and 2005 at a referral cancer centre. Glomerular filtration rate (GFR) was estimated with the abbreviated Modification in Diet and Renal Disease Study equation. Separate analysis was undertaken, with chronic kidney disease defined as GFR lower than 60 mL/min per 1.73 m(2) and GFR lower than 45 mL/min per 1.73 m(2). FINDINGS 171 (26%) patients had pre-existing chronic kidney disease before surgery. After surgery, the 3-year probability of freedom from new onset of GFR lower than 60 mL/min per 1.73 m(2) was 80% (95% CI 73-85) after partial nephrectomy and 35% (28-43; p<0.0001) after radical nephrectomy; corresponding values for GFRs lower than 45 mL/min per 1.73 m(2) were 95% (91-98) and 64% (56-70; p<0.0001), respectively. Multivariable analysis showed that radical nephrectomy remained an independent risk factor for patients developing new onset of GFR lower than 60 mL/min per 1.73 m(2) (hazard ratio 3.82 [95% CI 2.75-5.32]) and 45 mL/min per 1.73 m(2) (11.8 [6.24-22.4]; both p<0.0001). INTERPRETATION Because the baseline kidney function of patients with renal cortical tumours is lower than previously thought, accurate assessment of kidney function is essential before surgery. Radical nephrectomy is a significant risk factor for the development of chronic kidney disease and might no longer be regarded as the gold standard treatment for small, renal cortical tumours.


Annals of Surgical Oncology | 2003

Effect of papillary and chromophobe cell type on disease-free survival after nephrectomy for renal cell carcinoma.

Stephen D.W. Beck; Manish I. Patel; Mark E. Snyder; Michael W. Kattan; Robert J. Motzer; Victor E. Reuter; Paul Russo

BackgroundThe clinical staging of renal cortical tumors traditionally has not evaluated the potential effect of histological subtypes on survival. Evidence suggests that conventional clear cell renal cell carcinoma (RCC) and nonconventional clear cell RCC (chromophobe and papillary) have different metastatic potential. Using a large renal tumor database, we examined the effect of tumor histology on the pattern of metastasis and patient survival.MethodsAll patients with nonmetastatic renal cortical tumors undergoing partial or radical nephrectomy were identified from a renal tumor database between July 1989 and July 2002. Kaplan-Meier and Cox regression tests were used for statistical analysis.ResultsAnalysis revealed 1057 patients: 794 with conventional clear cell RCC, 157 with papillary RCC, and 106 with chromophobe RCC. Metastasis occurred in 95 conventional clear cell RCC, 9 papillary RCC, and 6 chromophobe RCC. Metastasis occurred in 95 conventional clear cell RCC, 9 papillary RCC, and 6 chromophobe RCC with a median follow-up of 34.6, 43.0, and 33.2 months, respectively. Using log-rank analysis, chromophobe and papillary RCC were associated with an improved disease-free survival at 5 years (P=.009 and .015, respectively). Multivariate analysis revealed tumor size, stage, and chromophobe histology as significant variables for disease progression.ConclusionsRenal cortical tumors have distinct histological subtypes with varying degrees of metastatic potential. Conventional clear cell RCC, which comprises two thirds of renal cortical tumors presenting with localized disease, has a less favorable outcome when compared with papillary and chromophobe RCC. Controlling for size and stage, chromophobe, and not papillary, RCC was a significant variable for disease progression compared with conventional clear cell RCC. Knowledge of renal cortical tumor histological subtype is critical for projecting prognosis, tailoring follow-up strategies, and designing clinical trials.


BJUI | 2006

Comparison of outcomes in elective partial vs radical nephrectomy for clear cell renal cell carcinoma of 4–7 cm

Atreya Dash; Andrew J. Vickers; Lee R. Schachter; Ariadne M. Bach; Mark E. Snyder; Paul Russo

To compare the outcomes of patients who had a elective partial nephrectomy (PN) or radical nephrectomy (RN) for clear cell renal cell carcinoma (RCC) of 4–7 cm.


Journal of Clinical Oncology | 2006

Renal Cell Carcinoma Recurrence After Nephrectomy for Localized Disease: Predicting Survival From Time of Recurrence

Ofer Yossepowitch; Joseph A. Pettus; Mark E. Snyder; Robert J. Motzer; Paul Russo

PURPOSE Prognostic factors for patients with metastatic renal cell carcinoma (RCC) are well established. However, the risk profile is unknown for patients with recurrent RCC after a nephrectomy for localized disease. PATIENTS AND METHODS From January 1989 to July 2005, we identified patients with localized RCC treated by nephrectomy who subsequently developed recurrent disease. We applied a validated prognostic scoring system previously developed for patients with metastatic RCC. Each patient was given a total risk score of 0 to 5, with one point for each of five prognostic variables (recurrence < 12 months after nephrectomy, serum calcium > 10 mg/dL, hemoglobin < lower limit of normal, lactate dehydrogenase > 1.5x upper limit of normal, and Karnofsky performance status < 80%). Patients were categorized into low- (score = 0), intermediate- (score = 1 to 2), and high-risk subgroups (score = 3 to 5). RESULTS Our final cohort included 118 patients, with a median survival time of 21 months from the time of recurrence. Median follow-up time for survivors was 27 months. Overall survival was strongly associated with risk group category (P < .0001). Low-risk, intermediate-risk, and high-risk criteria were fulfilled in 34%, 50%, and 16% of patients, respectively. Median survival time for low-risk, intermediate-risk, and high-risk patients was 76, 25, and 6 months, respectively. Two-year overall survival rates for low-risk, intermediate-risk, and high-risk patients were 88% (95% CI, 77% to 99%), 51% (95% CI, 37% to 65%), and 11% (95% CI, 0% to 24%), respectively. CONCLUSION At disease recurrence after nephrectomy for localized disease, a scoring system based on objective clinical and laboratory data provides meaningful risk stratification for both patient counseling and clinical trial entry.


BJUI | 2007

Impact of positive surgical margins in patients undergoing partial nephrectomy for renal cortical tumours

Eric O. Kwon; Brett S. Carver; Mark E. Snyder; Paul Russo

To evaluate the clinical outcome of patients undergoing partial nephrectomy (PN) for renal cortical tumours who had a positive surgical margin (SM), as recent studies have shown that a minimal SM is required to achieve equivalent disease‐free survival (DFS).


BJUI | 2004

Partial nephrectomy for patients with a solitary kidney: the Memorial Sloan-Kettering experience

Jeffery W. Saranchuk; A. Karim Touijer; Payam Hakimian; Mark E. Snyder; Paul Russo

A careful analysis of 54 patients with a solitary kidney and who had a partial nephrectomy is reported by authors from New York. They found it to be a safe procedure with an acceptable decline in renal function which stabilised during the first year. The requirement for temporary haemodialysis was low.


The Journal of Urology | 2006

Impact of Body Mass Index on Survival of Patients With Surgically Treated Renal Cell Carcinoma

S. Machele Donat; Elan W. Salzhauer; Nandita Mitra; Brent Yanke; Mark E. Snyder; Paul Russo

PURPOSE Population studies link increased BMI with an increased risk of cancer and cancer mortality and in particular a greater risk of RCC. We evaluated the impact of BMI and other clinical/pathological characteristics on survival in patients with RCC treated with radical or partial nephrectomy. MATERIALS AND METHODS Between 1995 and 2003 patients undergoing radical (760) or partial (399) nephrectomy for RCC were entered into a database. BMI data were available on 1,137 of 1,159 (98%). Demographic and clinical/pathological parameters were analyzed. World Health Organization BMI definitions (normal-less than 25 kg/m(2), overweight-25 to 29.9 kg/m(2), obese-30 kg/m(2) or more) were used. RESULTS A total of 75% of patients had greater than normal BMI with 472 (41.5%) overweight and 387 (34.0%) obese. Median followup was 33 months with a median overall survival of 110 months and a 5-year overall survival probability of 0.79. BMI categories were similar in age, gender, smoking status, presenting symptoms, tumor size, stage, and type of surgery. Significant increases in blood loss and operative time (p <0.05) were seen with increasing BMI. Although BMI 30 kg/m(2) or greater was associated with a higher proportion of clear cell histology (p = 0.002), it did not translate into an increased pathological stage, or incidence of metastasis. Multivariate analysis revealed age older than 65 years, systemic symptoms, surgery type, and pathological stage impacted overall survival (p <0.05). CONCLUSIONS Although an increased BMI was associated with a greater proportion of clear cell histology, comorbidity, and surgical morbidity, BMI did not adversely impact overall or progression-free survival.


BJUI | 2006

Renal cell carcinoma local recurrences: impact of surgical treatment and concomitant metastasis on survival.

J. James Bruno; Mark E. Snyder; Robert J. Motzer; Paul Russo

The local recurrence of renal cancer is an uncommon event, but it is often tempting to remove such recurrences surgically. Authors from the USA analysed the survival benefit of such a strategy in the presence and the absence of concomitant metastatic disease. They found that, in the absence of metastases, complete surgical resection of local recurrences is associated with improved survival.


BJUI | 2006

Mini‐flank supra‐11th rib incision for open partial or radical nephrectomy

Christopher J. DiBlasio; Mark E. Snyder; Paul Russo

Obesity is cited as a limiting factor in laparoscopy, and can limit instrument movements by the greater degree of port fixity, but this does not preclude this approach in obese patients. However, performing a radical or partial nephrectomy through an 8cm incision in an obese patient might compromise access and prove extremely difficult; the body mass index of the patients in the authors’ series is not mentioned. These patients often benefit the most from a laparoscopic procedure, having otherwise a greater risk of wound complications after open surgery.


Annals of Surgical Oncology | 2007

Partial penectomy for patients with squamous cell carcinoma of the penis: the Memorial Sloan-Kettering experience.

Ruslan Korets; Theresa M. Koppie; Mark E. Snyder; Paul Russo

BackgroundTo present our institution’s experience with squamous cell carcinoma (SCC) of the penis, with analysis of oncologic efficacy and survival.MethodsBetween 1989 and 2005, we identified 32 consecutive patients (median age, 61 years) with SCC of the penis managed with partial penectomy. Clinicopathologic variables were examined, and overall and disease-specific survival were determined.ResultsPathologic stage of the primary tumor was pTis in 1 patient (3%), pT1 in 11 (34%), pT2 in 16 (50%), and pT3 in 4 (13%). Pathologic grade was well differentiated in 9 patients (28%), moderately differentiated in 20 (63%), and poorly differentiated in 2 (6%). Twenty-five patients (78%) underwent inguinal lymph node dissection, with 15 (60%) demonstrating nodal metastases. Twenty-two patients (69%) underwent pelvic lymph node dissection; 21 were negative for pelvic nodal metastases, and 1 had grossly positive nodes. One patient developed local recurrence. After a mean follow-up of 34 months, overall survival was 56%. Numbers of patients alive and disease-free were 9 and 11 in the low-stage and advanced-stage groups, and 8 and 12 in the well and moderately differentiated groups, respectively. Both patients with poorly differentiated disease died of disease within 12 months from presentation.ConclusionsPartial penectomy for SCC of the penis provides excellent local control, with low recurrence rate, and acceptable maintenance of urinary and sexual function. Outcomes are generally poor, however, for patients with regional metastases, even in moderately differentiated disease. Future studies are needed to identify a reliable method of predicting regional metastases.

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Paul Russo

Memorial Sloan Kettering Cancer Center

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Michael W. Kattan

Case Western Reserve University

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Robert J. Motzer

Memorial Sloan Kettering Cancer Center

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Ariadne M. Bach

Memorial Sloan Kettering Cancer Center

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Andrew J. Vickers

Memorial Sloan Kettering Cancer Center

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Victor E. Reuter

Memorial Sloan Kettering Cancer Center

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Angel M. Serio

Memorial Sloan Kettering Cancer Center

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Ganesh V. Raj

University of Texas Southwestern Medical Center

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Joseph A. Pettus

Memorial Sloan Kettering Cancer Center

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