T1 Renal Masses Research Articles

Partial Nephrectomy for T1b Renal Cell Carcinoma: A Safe and

Partial Nephrectomy for T1b Renal Cell Carcinoma: A Safe and

Practice‐setting and surgeon characteristics heavily influence the decision to perform partial nephrectomy among American Urologic Association surgeons

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: There is great variability in the utilization of partial nephrectomy, but the causes of these variations are not well understood. The present study underscores the already observed phenomenon of surgical volume influencing surgical planning and outcomes, but it gets at why this might be so. We observe that high-volume renal surgeons have different thresholds of 'technical feasibility'. To investigate why there continues to be wide variability in the application of partial nephrectomy (PN) for treating small renal masses despite guidelines in the US and Europe stating that a PN is a standard of care for a patient with a T1 renal mass. In June 2009, 764 surgeon-members of the American Urologic Association (AUA) participated in a survey evaluating the management of renal masses. Renal mass complexity was graded by nephrometry score (NS). Multivariable logistic regression models with generalized estimating equations were constructed to evaluate how tumour, surgeon and practice-setting characteristics influence the use of PN. The survey response rate was 19%. Each urological surgeon responded to eight scenarios, providing 6112 evaluable cases. Tumour NS ranged from 4 to 10, and each unit increase in NS was associated with 59% increased likelihood of a surgeon offering RN on multivariable analysis (odds ratio [OR] = 1.59; 95% CI: 1.52-1.64). When holding patient and tumour characteristics constant, the following surgeon and practice-setting characteristics significantly increased the odds of offering a PN: increasing renal case volume (OR = 1.57; 95% CI: 1.27-1.95), academic practice (OR = 1.80; 95% CI: 1.42-2.29), increasing PN % volume (OR = 3.7; 95% CI: 2.46-5.55) and younger surgeon age (≤ 40 vs >50 years) (OR = 1.64; 95% CI: 1.35-1.96). The characteristics of a surgeon and the setting in which he or she practices influence the utilization of PN, the adherence to professional guidelines, and the threshold of tumour complexity at which a surgeon stops offering PN.

Functional Recovery After Partial Nephrectomy: Effects of Volume Loss and Ischemic Injury

We used what is to our knowledge a new method to estimate volume loss after partial nephrectomy to assess the relative contributions of ischemic injury and volume loss on functional outcomes. We analyzed the records of 301 consecutive patients who underwent conventional partial nephrectomy between 2007 and 2010 with available data to meet inclusion criteria. Percent functional volume preservation was measured at a median of 1.4 years after surgery. Modification of diet in renal disease-2 estimated glomerular filtration rate was measured preoperatively and perioperatively, and a median of 1.2 years postoperatively. Statistical analysis was done to study associations. Hypothermia or warm ischemia 25 minutes or less was applied in 75% of cases. Median percent functional volume preservation was 91% (range 38%-107%). Percent glomerular filtration rate preservation at nadir and late time points was 77% and 90% of preoperative glomerular filtration rate, respectively. On multivariate analysis percent functional volume preservation and warm ischemia time were associated with nadir glomerular filtration rate while only percent functional volume preservation was associated with late glomerular filtration rate (each p <0.001). Late percent glomerular filtration rate preservation and percent functional volume preservation were directly associated (p <0.001). Recovery of function to 90% or greater of percent functional volume preservation predicted levels was observed in 86% of patients. In patients with de novo postoperative stage 3 or greater chronic kidney disease, percent functional volume preservation and Charlson score were associated with late percent glomerular filtration rate preservation. Warm ischemia time was not associated with late functional glomerular filtration rate decreases in patients considered high risk for ischemic injury. In this cohort volume loss and not ischemia time was the primary determinant of ultimate renal function after partial nephrectomy. Technical modifications aimed at minimizing volume loss during partial nephrectomy while still achieving negative margins may result in improved functional outcomes.

Long-Term Outcomes of Renal Tumor Radio Frequency Ablation Stratified by Tumor Diameter: Size Matters

Renal tumor size influences the efficacy of radio frequency ablation but identification of confident size cutoffs has been limited by small numbers and short followup. We evaluated tumor size related outcomes after radio frequency ablation for patients with adequate (greater than 3 years) followup. We identified 159 tumors treated with radio frequency ablation as primary treatment. Disease-free survival was defined as the time from definitive treatment to local recurrence, detection of metastasis or the most recent imaging showing no evidence of disease. Patients were evaluated with contrast enhancing imaging preoperatively, and at 6 weeks, 6 months and at least annually thereafter. Median tumor size was 2.4 cm (range 0.9 to 5.4) with a median followup of 54 months (range 1.5 to 120). Renal cell carcinoma was confirmed in 72% of the 150 tumors that had pre-ablation biopsy (94%). The 3 and 5-year disease-free survival was comparable at 92% and 91% overall, and was dependent on tumor size, being 96% and 95% for tumors smaller than 3.0 cm and 79% and 79%, respectively, for tumors 3 cm or larger (p=0.001). Most failures (14 of 18) were local, either incomplete ablations or local recurrences. This is an intent to treat analysis and, therefore, includes patients ultimately found to have benign tumors, although outcomes were comparable in patients with cancer. Radio frequency ablation treatment success of the small renal mass is strongly correlated with tumor size. Radio frequency ablation provides excellent and durable outcomes, particularly in tumors smaller than 3 cm. Of tumors 3 cm or larger, approximately 20% will recur such that alternative treatment techniques should be considered. However, most treatment failures are local and are often successfully treated with another ablation session.

Understanding the Role of Percutaneous Biopsy in the Management of Patients With a Small Renal Mass

To evaluate patient and tumor characteristics associated with percutaneous renal mass biopsy (RMB) among patients with small renal masses (SRMs) and assessed the impact on clinical decision-making. For 204 consecutive patients presenting with a clinical stage T1 renal mass at our institution, we collected data regarding patient demographics, comorbidity, renal function, anatomic factors, and treatment plan. We then assessed the association between these characteristics and receipt of RMB, and between biopsy results and initial treatment decision. Among 204 patients, 78 (38%) received RMB. Of the demographic and physiological parameters, only non-Caucasian race and family history of renal cell carcinoma were associated with biopsy (P<.05). In contrast, RMB was significantly associated with several anatomic factors, including larger tumor size, solitary kidney, juxta-hilar tumor location, greater body mass index (BMI), and high-complexity nephrometry score (P<.05). On multivariable analysis, only BMI>25 kg/m2, juxta-hilar location, and high-complexity nephrometry score remained significantly associated with RMB (P<.05). Biopsy was performed in a greater proportion of patients who ultimately underwent radical nephrectomy vs nephron-sparing surgery (NSS) (P=.04). Furthermore, RMB results directly impacted treatment, with active surveillance more frequent among patients with benign or favorable histology and surgical management more common among patients with more aggressive disease (P<.001). At our institution, one-third of patients presenting with a SRM undergo RMB, most commonly among patients with complicated anatomic and/or tumor considerations. Because these factors may limit the feasibility of NSS, biopsies are being used to guide decision-making aimed at minimizing total kidney loss.

Editorial Comment

This report considers the factors that predict the use of renal mass biopsy (RMB) for patients with clinical Stage T1 renal masses. The population consisted of 204 patients presenting at a single institution with a preference for RMB, and 38% underwent RMB as a part of their evaluation. The authors report that the strongest predictors of RMB were complicated anatomy according to the RENAL classification, juxtahilar location, or solitary kidney. As such, 1 of the main objectives of RMB in this series appeared to differentiate the operative approaches in cases with potentially challenging anatomy.

Oncological outcomes of partial nephrectomy for renal carcinoma greater than 4 cm

To provide the clinical evidence and benefits of performing partial nephrectomy for renal tumors greater than 4 cm. Partial nephrectomy was historically performed only for the essential indications of a tumor in a functional or anatomical solitary kidney or in the face of bilateral renal tumors. Partial nephrectomy has now emerged as an oncologically equivalent operation to radical nephrectomy for T1a tumors (<4 cm) with the added benefit of renal functional preservation which can prevent or delay the onset of chronic kidney disease (CKD). CKD is an independent risk factor for hospitalization events, cardiovascular disease, and worse overall survival. Recent evidence has demonstrated that partial nephrectomy also provides equivalent oncological results for larger renal tumors including those of 4-7 cm and even for greater than 7 cm, whenever technically feasible with the continued added benefit of renal functional preservation. Partial nephrectomy is effectively performed using both open surgical techniques and increasingly by minimally invasive approaches although the latter is technically challenging. Despite the mounting clinical evidence that partial nephrectomy is an effective and preferable approach to the T1 renal mass, it remains markedly underutilized in the USA and abroad. The overzealous use of radical nephrectomy for the T1 renal mass, by whatever surgical approach, must now be considered detrimental to the long-term health of the kidney tumor patient.

Impact of Tumor Size on Renal Function and Prediction of Renal Insufficiency After Radical Nephrectomy in Patients With Renal Cell Carcinoma

From the perspective of oncological and functional outcomes partial nephrectomy is considered standard surgery for small renal tumors 4 cm or less. However, radical nephrectomy is commonly done for small tumors. It is important to predict postoperative renal function in patients to choose the most optimal surgical procedure. We retrospectively reviewed the records of 271 patients treated with radical nephrectomy for renal cell carcinoma. Associations of tumor size and clinical variables with renal function were analyzed. Preoperatively the mean ± SD glomerular filtration rate was 74.38 ± 17.70 ml per minute/1.73 m(2) and 56 patients (20%) had renal insufficiency (glomerular filtration rate less than 60 ml per minute/1.73 m(2)). The mean decrease in the glomerular filtration rate after radical nephrectomy was 24.2 ± 12.40 ml per minute/1.73 m(2) (31.5% ± 15%). Of 215 patients with a preoperative glomerular filtration rate of 60 ml per minute/1.73 m(2) or greater 165 (77%) had new onset renal insufficiency. Age, tumor size, preoperative glomerular filtration rate and hypertension were significantly associated with new onset renal insufficiency. Multivariate analysis revealed that age 60 years or greater, tumor size 7 cm or less and the preoperative glomerular filtration rate were independent risk factors for new onset renal insufficiency (p <0.05). Finally, we developed a predictive model for new onset renal insufficiency after radical nephrectomy. Tumor size 7 cm or less, age 60 years or greater and a decreased preoperative glomerular filtration rate were significant risk factors for new onset renal insufficiency in patients treated with radical nephrectomy. Partial nephrectomy might be considered an option according to the risk of postoperative renal insufficiency, especially in elderly patients with a tumor of 7 cm or less.

Complications After Robotic Partial Nephrectomy at Centers of Excellence: Multi-Institutional Analysis of 450 Cases

We evaluated the incidence of perioperative complications after robotic partial nephrectomy. We retrospectively reviewed the records of patients treated with robotic assisted partial nephrectomy across the 4 participating institutions. Demographic, blood loss, warm ischemia time, and intraoperative and postoperative complication data were collected. All complications were graded according to the Clavien classification system. A total of 450 consecutive robotic assisted partial nephrectomies were done between June 2006 and May 2009. Overall 71 patients (15.8%) had a complication, including intraoperative and postoperative complications in 8 (1.8%) and 65 (14.4%), respectively. Hemorrhage developed in 2 patients (0.2%) intraoperatively and in 22 (4.9%) postoperatively. Seven patients (1.6%) had urine leakage. As classified by the Clavien system, complications were grade I-II in 76.1% of cases and grade III-IV in 23.9%. Robotic assisted partial nephrectomy was converted to open or conventional laparoscopic surgery in 3 patients (0.7%) and to radical nephrectomy in 7 (1.6%). There were no deaths. Current data indicate that robotic assisted partial nephrectomy is safe. Most postoperative complications are Clavien grade I or II, or can be managed conservatively.

Regional trends of renal mass management in the Southeast.

e16562 Background: Current management of renal masses emphasizes nephron sparing procedures due to similar oncologic outcomes while potentially decreasing renal and cardiovascular morbidity compared to radical nephrectomy. According to the AUA guidelines radical nephrectomy is overly utilized leading to increased morbidity from chronic renal insufficiency. Partial nephrectomy is now considered the treatment of choice in T1 renal masses. Here, we analyzed epidemiologic data from the southern states of Virginia, VA, and Kentucky, KY, to assess compliance with a changing standard of care. Methods: Using the Department of Health Patient Level Database System reported via the Thomson Reuters Polaris Suite, we identified all patients hospitalized for a primary International Classification of Disease (9th revision; ICD-9) code suggestive of malignant renal mass and compared the prevalence of nephrectomy, partial nephrectomy, and ablative procedures in VA and KY. Data analysis was performed using Microsoft Excel 2007 for both academic and community hospitals. Results: We identified patients treated in VA and KY from 2004-2009. The proportion of radical nephrectomies has been steadily decreasing from 2004 with peak prevalence in 2004 for both KY and VA. The proportion of nephron sparing procedures has been increasing from 2004 to 2007 with peak prevalence in 2007 in VA and 2009 in KY. By 2009 nephron sparing procedures accounted for 32% and 31% of all renal mass surgery in KY and VA, respectively. The proportion of all renal procedures performed that were radical nephrectomies has decreased in both academic and community hospitals. Academic institutions experienced an earlier and more rapid rise in nephron sparing procedures in both VA and KY. Conclusions: VA and KY inpatient data indicate practice patterns for management of renal masses has been changing with increased use of nephron sparing therapies relative to radical nephrectomy. Furthermore, academic hospitals appear to have adopted nephron sparing therapies earlier than community hospitals. However, given that partial nephrectomies are the recommended standard of care for T1 renal masses by the AUA, the percentage of these procedures being performed are still surprisingly low.

Optimal Freeze Cycle Length for Renal Cryotherapy

To our knowledge the optimal freeze cycle length in renal cryotherapy is unknown. Ten-minute time based freeze cycles were compared to temperature based freeze cycles to -20C. Laparoscopic renal cryotherapy was performed on 16 swine. Time based trials consisted of a double 10-minute freeze separated by a 5-minute thaw. Temperature based trials were double cycles of 1, 5 or 10-minute freeze initiated after 1 of 4 sensors indicated -20C. A 5-minute active thaw was used between freeze cycles. Control trials consisted of cryoneedle placement for 25 minutes without freeze or thaw. Viability staining and histological analysis were done. There was no difference in cellular necrosis between any of the temperature based freeze cycles (p = 0.1). Time based freeze cycles showed more nuclear pyknosis, indicative of necrosis, than the 3 experimental freeze cycles for the renal cortex (p = 0.05) but not for the renal medulla (p = 0.61). Mean time to -20C for freeze cycle 1 was 19 minutes 10 seconds (range 9 to 46 minutes). In 4 of 21 trials (19%) -20C was never attained despite freezing for 25 to 63 minutes. There was no difference in immediate cellular necrosis among double 1, 5 or 10-minute freeze cycles. Cellular necrosis was evident on histological analysis for trials in which -20C was attained and in freeze cycles based on time alone. With a standard 10-minute cryoablation period most treated parenchyma 1 cm from the probe never attained -20C. Cell death appeared to occur at temperatures warmer than -20C during renal cryotherapy.

Image Guided Percutaneous Probe Ablation for Renal Tumors in 65 Solitary Kidneys: Functional and Oncological Outcomes

We evaluated the oncological and functional outcomes of computerized tomography guided percutaneous cryotherapy or radio frequency ablation of kidney tumors in patients with a solitary kidney. We reviewed the medical charts of patients with a solitary kidney who underwent percutaneous probe ablation for renal masses at our institution from April 2002 through March 2010. Followup consisted of computerized tomography or magnetic resonance imaging 1 day postoperatively, at 3, 6 and 12 months, and annually thereafter. Serum creatinine and estimated glomerular filtration rate were used to measure renal function. The cryotherapy and radio frequency ablation groups were compared for demographics, the 2-year actuarial survival rate and renal function. Overall 65 patients were included in this retrospective analysis, of whom 29 (44.6%) underwent cryotherapy and 36 (55.4%) underwent radio frequency ablation. Median followup was 15.1 (IQR 4.4 to 32.9) and 38.8 months (13.8 to 50.7), respectively. The 2 groups were comparable in median age, body mass index, American Society of Anesthesiologists score, tumor size and preoperative estimated glomerular filtration rate. The 3 primary treatment failures, including 1 after cryotherapy and 2 after radio frequency ablation, were successfully re-treated with thermal ablation. There were 14 recurrences after radio frequency ablation and 3 after cryotherapy. Two-year actuarial overall, cancer specific, recurrence-free and metastasis-free survival rates for cryotherapy vs radio frequency ablation were 89% vs 93%, 100% vs 96%, 69% vs 58% and 86% vs 91%, respectively. For each group no significant decrease in renal functional parameters was found at the latest followup visit. Computerized tomography guided percutaneous probe ablation represents a safe treatment option in surgical patients at high risk with a solitary kidney. It provides low morbidity, acceptable short-term cancer control and minimal clinical impact on postoperative renal function.

Limited Warm Ischemia During Elective Partial Nephrectomy has Only a Marginal Impact on Renal Functional Outcomes

Ischemic damage during partial nephrectomy increases with each minute of warm ischemia, leading some groups to advocate hypothermia in all cases or partial nephrectomy without vascular occlusion as a primary technique. The renal functional implications of these approaches have not been well studied in patients who undergo elective partial nephrectomy. We evaluated early and late renal functional outcomes in 1,132 patients with 2 functioning kidneys and normal preoperative serum creatinine who underwent partial nephrectomy without regional ischemia (58), with less than 30-minute warm ischemia (809) or with cold ischemia (265). The preoperative, postoperative and latest glomerular filtration rates were not significantly different in the 3 groups. At latest followup the relative decrease in renal function was less in cases without regional ischemia than in those with less than 30-minute warm ischemia and those with cold ischemia (0.5% vs 13% and 11%, respectively, p <0.001). In part this reflected selection bias since tumor size and the amount of parenchyma removed were lowest in that group (p <0.001). On multivariate analysis the percent of parenchyma preserved and the baseline glomerular filtration rate were strongly associated with the postoperative and latest glomerular filtration rates (p <0.001) but the partial nephrectomy approach was not (p >0.05). Adverse short or long-term renal functional outcomes were marginally increased in patients with 20 to 30-minute warm ischemia. However, such events were uncommon and renal failure developed in only 4 of 1,132 patients (less than 0.4%). During elective partial nephrectomy a warm ischemia time of less than 20 minutes is not associated with clinically relevant functional loss compared to that of alternative techniques. However, longer warm ischemia time may correlate with ischemic injury and should be avoided.

690 PREDICTING PATIENTS AT HIGH RISK FROM NON-EXTIRPATIVE TREATMENT OF LOCALIZED RENAL MASSES USING PRE-OPERATIVE FACTORS

You have accessJournal of UrologyKidney Cancer: Evaluation and Staging1 Apr 2011690 PREDICTING PATIENTS AT HIGH RISK FROM NON-EXTIRPATIVE TREATMENT OF LOCALIZED RENAL MASSES USING PRE-OPERATIVE FACTORS Rebecca L. O'Malley, MD Matthew H. Hayn, MD Katherine A. Brewer, Michael A. Poch, MD Hyung L. Kim, andMD Thomas SchwaabMD, PhD Rebecca L. O'MalleyRebecca L. O'Malley Buffalo, NY More articles by this author , Matthew H. HaynMatthew H. Hayn Buffalo, NY More articles by this author , Katherine A. BrewerKatherine A. Brewer Buffalo, NY More articles by this author , Michael A. PochMichael A. Poch Buffalo, NY More articles by this author , Hyung L. KimHyung L. Kim Los Angeles, CA More articles by this author , and Thomas SchwaabThomas Schwaab Buffalo, NY More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.1657AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Due to increasing detection of incidental renal masses, and the many possibilities for management, identifying reliable means of selecting patients (pts) in need of extirpative therapy is paramount. Existing nomograms include operative factors or symptomatic pts making them difficult to apply in pre-treatment decision-making for pts with the asymptomatic, clinical stage T1 renal mass. METHODS Using our institutional renal tumor database, we identified pts who were candidates for elective partial nephrectomy (solitary tumors ≤ 7cm, no venous involvement, creatinine ≤ 1.5 mg/dL and normal contralateral kidney). High-risk disease (HRD) was defined as pathologic stage ≥T3 or grade ≥3. Pre-operative variables hypothesized to predict risk of malignancy and HRD were analyzed including: age, gender, race, smoking history (hx), cancer hx, hx of hypertension (HTN), body mass index (BMI), Charlson comorbidity index (CCI), glomerular filtration rates (eGFR), as estimated by the Chronic Kidney Disease Epidemiology Collaboration formula, tumor size, and tumor centrality (defined as abutting renal sinus or collecting system). RESULTS A total of 309 pts were identified, with mean age, BMI and eGFR of 61 years, 31 kg/m2 and 76 ml/min/1.73m2, respectively. The cohort was mostly male (60%) and Caucasian (89%) with a CCI ≥1 in 42%. Hx of cancer was seen in 12%, HTN in 60% and smoking in 57%. Mean tumor size was 3.6 ± 1.6 cm, 64% of which were central. Malignancy was found in 83.1% and HRD in 29.5%. On univariable analysis male gender and tumor size predicted malignancy (OR 1.96, p=0.29 and OR 1.88, p<0.001, respectively). Tumor size and centrality predicted HRD (OR 1.39, p<0.001 and 3.05, p=0.002, respectively). Tumor size > 4cm correlated with both malignancy and HRD (OR 4.09, p<0.001 and OR 2.46, p<0.001, respectively). On multivariable analysis, male gender and tumor size remained predictive of malignancy (OR 2.59, p=0.015 and OR 1.48, p=0.031, respectively), while centrality was marginally predictive (OR 2.27, p=0.062). Age and tumor size were the only factors marginally predictive of HRD (OR 1.02, p=0.073 and OR 1.26, p=0.072, respectively). When factors were combined, 100% of men with a central tumor >4 cm had malignancy with a risk of HRD of 2.43 (p=0.029). CONCLUSIONS Male gender, tumor size > 4cm and central tumors portend a high risk of malignancy and HRD. If validated, these factors could serve as the basis for a pre-operative nomogram to aid in identifying pts at high risk from non-extirpative management of a localized renal mass. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e278 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Rebecca L. O'Malley Buffalo, NY More articles by this author Matthew H. Hayn Buffalo, NY More articles by this author Katherine A. Brewer Buffalo, NY More articles by this author Michael A. Poch Buffalo, NY More articles by this author Hyung L. Kim Los Angeles, CA More articles by this author Thomas Schwaab Buffalo, NY More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

Intraoperative Conversion From Partial to Radical Nephrectomy at a Single Institution From 2003 to 2008

Little information exists on conversion from partial to radical nephrectomy. We assessed the intraoperative reasons and predictive factors for conversion in a contemporary series of patients undergoing partial nephrectomy. We identified all patients at our institution who underwent open or laparoscopic partial nephrectomy with conversion to radical nephrectomy between 2003 and 2008. Renal function was assessed by the glomerular filtration rate using the modification of diet in renal disease equation. We used logistic regression analysis to determine whether tumor site, tumor size, body mass index, American Society of Anesthesiologists score, age or gender was associated with the conversion risk. The rate of conversion to radical nephrectomy was 6% (61 of 1,029 patients). In the open partial nephrectomy group 59 of 865 cases (7%, 95% CI 5-9) and in the laparoscopic partial nephrectomy group 2 of 164 (1.2%, 95% CI 0.01-4) were converted. The most common reasons for conversion were invasion of hilar structures, size discrepancy and insufficient residual kidney. Patients with conversion were more likely to have larger tumors (per 1 cm increase OR 1.41, 95% CI 1.24-1.59), a central site (central vs peripheral OR 7.74, 95% CI 3.98-15) and a lower preoperative glomerular filtration rate (per 10 ml/minute/1.73 m(2) OR 0.78, 95% CI 0.67-0.91), and present with symptoms (any vs none OR 2.78, 95% CI 1.54-5.04) than those without conversion. The median postoperative glomerular filtration rate was 46 vs 61 ml/minute/1.73 m(2) in patients with vs without conversion. Conversion to radical nephrectomy was rare in patients undergoing partial nephrectomy in this series. Increasing tumor size, central site, lower preoperative glomerular filtration rate and symptoms at presentation were associated with an increased risk of conversion, which increases the likelihood of chronic kidney disease postoperatively.

Small renal masses: current concepts regarding the natural history and reflections on the American Urological Association guidelines

Although surgical resection is the current standard for treatment of small (<4 cm) renal cortical neoplasms, active surveillance remains an option in selected patients depending on tumor characteristics and surgical risk. We review the natural history of small renal masses according to the current literature, and highlight issues regarding the recent guidelines for the management of T1 renal masses put forth by the American Urological Association. The natural history of small renal masses is still largely unknown; however, initial size or volume of the mass seems to predict the risk of malignancy in retrospective studies. A new study found that growth rate is inversely related to initial tumor volume, with smaller masses growing faster in the beginning and decreasing in rate of growth as they enlarge. Biomarkers such as carbonic anhydrase IX, vascular endothelial growth factor, and CD147 have demonstrated some value in predicting tumor characteristics and prognosis in renal cell carcinoma. Finally, we suggest modifications to the new American Urological Association guidelines based on the authors' experience in order to optimize the management of renal cortical neoplasms. The natural history of small renal masses is not completely understood. Growth rate and tumor size are factors shown to be predictive of tumor biology. Currently, there are no specific tumor markers to determine initial risk or progression to metastatic disease; however, investigation into new molecules is being undertaken. The guidelines presented by the American Urological Association give a formal framework for the management of T1 renal cortical neoplasms; however, we site specific modifications and recommend that they be considered when evaluating patients for treatment.

7-Year Oncological Outcomes After Laparoscopic and Open Partial Nephrectomy

Open partial nephrectomy has proven long-term oncological efficacy. Long-term outcomes of laparoscopic partial nephrectomy are pending. We present the long-term outcomes of patients undergoing laparoscopic or open partial nephrectomy for a single cT1 renal cortical tumor 7 cm or less. Of 2,246 patients undergoing partial nephrectomy for a single cT1 tumor (1999 to 2008), minimum 7-year followup was available in 77 and 310, and minimum 1-year followup was available in 672 and 944 after laparoscopic and open partial nephrectomy, respectively. Survival and recurrence data obtained from medical records, radiographic reports and patient contact were analyzed retrospectively. Median followup after laparoscopic and open partial nephrectomy was 4.0 and 5.7 years, respectively. Oncological outcomes were excellent in both groups. On multivariable analysis predictors of all cause mortality included advancing age (p <0.0001), comorbidity (p <0.0001) and preoperative renal dysfunction (p = 0.0001) but not tumor size (p = 0.6) or operative approach (laparoscopic vs open partial nephrectomy, p = 0.06). Cancer recurred infrequently and only rarely caused mortality after laparoscopic or open partial nephrectomy. At 7 years metastasis-free survival was 97.5% and 97.3% (p = 0.47) after laparoscopic and open partial nephrectomy, respectively. After accounting for baseline differences between the cohorts using propensity score matching 7-year metastasis-free survival was similar after laparoscopic and open partial nephrectomy. Laparoscopic and open partial nephrectomy appear to provide similar long-term overall and cancer specific survival in patients undergoing partial nephrectomy for clinical stage T1 (7 cm or less) renal cortical tumors. Oncological outcomes at 7 years after laparoscopic and open partial nephrectomy are excellent with the majority (97%) of patients experiencing metastasis-free survival.

Renal Cell Carcinoma and Prognostic Factors Predictive of Survival

We congratulate Haferkamp et al.1 for their work trying to identify prognostic factors predictive of survival for patients with renal cell carcinoma (RCC) who undergo nephron-sparing surgery for imperative indications. Although in the past decade, there has been a trend to move from radical nephrectomy to nephron preservation, many renal units are still lost unnecessarily. Identifying those patients at a higher risk for metastatic disease and those who are likely to fail local therapy is of paramount importance. In the present study, the authors excluded patients with von Hippel-Lindau (VHL) syndrome, because these patients are prone to develop bilateral multifocal recurrent clear cell renal carcinomas. However, the reader should be aware that there are other hereditary syndromes besides VHL that predispose to the development of bilateral and/or multifocal renal cell carcinoma. These include patients with hereditary papillary renal carcinoma (HPRC) who develop bilateral papillary type 1 RCC, hereditary leiomyomatosis RCC (HLRCC) patients who tend to form aggressive papillary type 2 RCC, Birt-Hogg-Dube’ (BHD) patients who may develop a whole spectrum of tumors from benign oncocytomas to chromophobe RCC to aggressive clear cell RCC, and several other less-recognized syndromes, such as tuberous sclerosis and succinate-dehydrogenase-B deficiency.2 The above-mentioned syndromes may have multifocal RCC as a sole manifestation or as a constituent of a complex multiorgan involvement. Therefore, caution should be used in evaluating a study that excludes only VHL patients but not other hereditary forms of RCC. Additionally, there is a great variability of aggressiveness of lesions in patients with multifocal RCC. Unfortunately, the authors fail to delineate the type of patients who fit in the category of “imperative indications.” Were there patients with solitary renal units due to contralateral nephrectomy or congenital absence of the contralateral kidney? If the contralateral kidney was lost due to cancer, which pathological variables were analyzed? Predicting cancer-specific survival from resection of a T1 renal mass from a solitary kidney may not be driving the oncologic outcome if the same patient had a contralateral nephrectomy for a T3 disease. Because 50% of the cohort had bilateral disease, pathological information about contralateral kidney would be of great value and could provide additional predictors of poor outcome. Perhaps, a surprising finding of similar cancer-specific survival between T1, T2, and T3 groups may be explained by the confounding effects of contralateral pathology. The authors also evaluated the effect of multifocality in their analysis. It has been shown that multifocal RCC is much more prevalent than originally believed, and ranges from 5–25% in the literature.3,4 The problem with the study of multifocal RCC is our current inability to determine whether a second renal tumor in the same or the contralateral kidney is indeed part of multifocal disease or simply a recurrence or metastasis from a previously operated tumor. Without a specific genetic study designed to evaluate the clonal origin of each mass found, it is impossible to determine whether patients have multifocal, recurrent, or metastatic disease.5–7 Had recurrences been counted as multifocality, the assignment of patients to the different groups in the study may have affected the statistical analysis. The opposite also could be true. Because approximately 20% of lesions are missed by current imaging techniques both preoperatively and intraoperatively, patients assigned to the unifocal group may have actually had multifocal disease. This would have influenced the assignment of patients into various groups being analyzed and ultimately accounted for the lack of statistical significance between unifocal vs. multifocal groups and unilateral vs. bilateral groups. Although the present study evaluates patients spanning almost three decades, one of the major drawbacks is the fact that it may not have enough events to achieve statistical power.1 This is evident by the fact that well-known prognostic factors for cancer-specific survival (CSS), such as clinical stage (Tables 2, 3, 4), did not achieve statistical significance in this study. Therefore, it is likely that a type II error is present in evaluating the variables responsible for CSS. Furthermore, the authors attempted to perform multivariate analyses of variables that were not significant on univariate analysis and the statistical validity of this analysis is questionable. Finally, the authors found a “tendency” toward unfavorable prognosis in the case of positive surgical margins. Had there been more events, this tendency may have become statistically significant or completely disappeared. Moreover, the authors suggest doing everything in one’s hands to avoid having positive surgical margins, including radical nephrectomy. Although we also strongly advocate appropriate surgery with negative surgical margins, the reader should be aware of recent data showing that positive surgical margins do not jeopardize survival outcomes in patients who undergo nephron-sparing surgery.8 In addition, loss of nephrons and its consequent renal insufficiency subjects patients to an increased risk for cardiovascular disease and death.9,10 Thus, we encourage surgeons to attempt nephron-sparing techniques whenever feasible.

Guideline for Management of the Clinical T1 Renal Mass

Guideline for Management of the Clinical T1 Renal Mass

LAPAROSCOPIC RADICAL NEPHRECTOMY FOR LARGE (GREATER THAN 7 CM, T2) RENAL TUMORS

Laparoscopic radical nephrectomy has emerged as a standard of care in appropriate candidates with clinical stage T1 renal tumors (7 cm or less). Herein we present our experience with laparoscopic radical nephrectomy for clinical stage T2 tumors (greater than 7 cm). Patients undergoing laparoscopic radical nephrectomy between September 1997 and July 2003 were retrospectively subdivided into group LAPT1-166 with tumor size 7 cm and group LAPT2-65 with tumor size greater than 7 cm. Also, group LAPT2 was compared with a group of 34 contemporary, comparable patients undergoing open radical nephrectomy for tumor greater than 7 cm (group OPENT2). Compared with group LAPT1, group LAPT2 had younger patients, larger tumors and greater blood loss (100 vs 200 ml) (each p <0.001). Importantly operative time, analgesic requirements, hospital stay, and convalescence and complication rates were comparable. Group LAPT2 and group OPENT2 patients had similar sized tumors (9.2 and 9.9 cm, respectively) but shorter operative time (p = 0.03), lesser blood loss (p <0.001), shorter hospital stay (p <0.001) and more rapid convalescence (p = 0.02) occurred in LAPT2. Laparoscopic radical nephrectomy for stage T2 renal masses (greater than 7 cm) is feasible and efficacious. Laparoscopic nephrectomy offers the advantages of decreased blood loss, shorter hospital stay and more rapid recovery over open radical nephrectomy for comparable tumors greater than 7 cm. Although surgical outcomes are comparable with laparoscopic radical nephrectomy for smaller tumors (7 cm or less), adequate laparoscopic experience is necessary before performing radical nephrectomy for large T2 tumors.