Treatment of Patients With Small Renal Masses: A Survey of the American Urological Association

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1 Treatment of Patients With Small Renal Masses: A Survey of the American Urological Association Rodney H. Breau,*, Paul L. Crispen,* Sarah M. Jenkins, Michael L. Blute and Bradley C. Leibovich From the Department of Urology (RHB, MLB, BCL), and Division of Biomedical Statistics & Informatics (SMJ), Mayo Clinic, Rochester, Minnesota, and Division of Urology, University of Kentucky, Lexington, Kentucky (PLC) Purpose: We surveyed American Urological Association members to determine factors that influence the treatment of patients with small renal masses. Materials and Methods: In June 2009 American Urological Association members were solicited to complete an online survey. Respondents were asked their preferred treatment for 8 cases and 3 index patients. In each case computerized tomographic axial and schematic coronal images were provided. Results: A total of 759 active urologists with varied training backgrounds and clinical practice settings completed the survey. Tumor size (OR 8.4, 95% CI ), tumor depth (OR 19.2, 95% CI ) and tumor location (OR 24.0, 95% CI ) were markedly associated with preference for radical nephrectomy instead of partial nephrectomy. Fellowship trained urologists (OR 0.4, 95% CI ) and urologists at academic hospitals (OR 0.6, 95% CI ) were less likely to choose radical nephrectomy. Respondents were more likely to choose active surveillance in an older patient (OR 2.7, 95% CI ) or in a patient with comorbidities (OR 10.0, 95% CI ). Urologists were less likely to choose active surveillance for a 4 vs 2 cm tumor (OR 0.18, 95% CI ). Active surveillance was chosen more often if the tumor was perihilar vs mid kidney (OR 2.0, 95% CI ) or polar (OR 2.1, 95% CI ). Conclusions: There is considerable heterogeneity in the treatment of patients with clinical T1a tumors. Several factors explain these differences as selected treatments are independently associated with tumor, patient and urologist factors. Key Words: carcinoma, renal cell; nephrectomy; cross-sectional studies RENAL function significantly impacts quality of health and is associated with cardiovascular events and overall mortality. 1 This is of particular concern for patients with SRMs as most will not die of RCC but many will have renal dysfunction. Observational studies reveal that PN is associated with equivalent cancer cure, improved postoperative renal function, decreased cardiovascular events and improved overall survival compared to RN. 2 5 These findings have encouraged urologists to consider nephron sparing options for patients with SRMs. Despite increasing evidence supporting PN for small renal masses, many urologists continue to perform RN in these patients. 6 The use of RN is justified for a poorly functioning kidney. However, there may be other factors that influence the decision to pursue RN including perceived risk of Abbreviations and Acronyms AS active surveillance AUA American Urological Association GFR glomerular filtration rate MIS minimally invasive surgery PN partial nephrectomy RCC renal cell carcinoma RN radical nephrectomy SRM small renal mass Submitted for publication June 2, Supported by Grant Number 1 UL1 RR from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH) and the NIH Roadmap for Medical Research. Its contents are solely the responsibility of the authors and do not necessarily represent the official view of the NCRR or NIH. Information on the NCRR is available at Information on Reengineering the Clinical Research Enterprise can be obtained at * Equal study contribution. Correspondence: Department of Urology, Mayo Clinic, 200 First St. SW, Rochester, Minnesota (telephone: ; FAX: ; rodneybreau@yahoo.ca). See Editorial on page /11/ /0 Vol. 185, , February 2011 THE JOURNAL OF UROLOGY Printed in U.S.A by AMERICAN UROLOGICAL ASSOCIATION EDUCATION AND RESEARCH, INC. DOI: /j.juro

2 408 SMALL RENAL MASS SURVEY PN complications or lack of technical facility. Thermal ablation and AS have emerged as alternative treatment options for select patients with SRMs. However, ideal candidates for these options have yet to be defined. With this survey we determined factors that influence urologists treatment of patients with renal masses up to 4 cm in diameter. METHODS Recruitment In June 2009 AUA members with a listed address were invited to participate in the AUA small renal mass survey. Second and third wave requests were sent 1 week and 3 weeks following the original invitation . AUA members were provided a hyperlink to an online survey that was linked to a secured database. The survey was closed on July 31, Survey The survey was composed of 5 sections of demographics, training, evaluation of SRMs, management of SRMs and case examples. Demographic information included age, geographic location, years in practice and practice setting (academic, nonacademic, solo or group). Participants indicated if they received training in MIS and if they completed a post-residency fellowship. Respondents reported the number of patients with SRMs evaluated each year, how renal function is assessed in these patients and when they believe renal tumor biopsy is warranted. Participants also provided the number of various renal procedures they perform or refer to others to perform. Two general questions were posed in the survey. Participants were asked to rate the importance of various factors when choosing to perform radical or partial nephrectomy for a SRM, and to rate the importance of various factors when choosing treatment of a SRM (RN, PN or thermal ablation) compared to AS. Cases Participants were presented with 8 clinical cases. For each case a coronal drawing and an axial computerized tomographic image were provided (fig. 1). Cases varied by tumor size (2 or 4 cm), location (pole, mid pole or perihilar) and depth (completely endophytic or approximately mesophytic). In all cases tumors were described to the participant as asymptomatic, solitary, sporadic, solid and enhanced on cross-sectional imaging. In each case the respondent was asked to select a first choice in management (RN, PN, thermal ablation or AS). For each of the 8 cases urologists were asked to provide responses for 3 index patients (fig. 1). Respondents were instructed to assume kidneys had equal function (50%- 50% relative renal function) and that index patients had no medical conditions that would preclude surgical intervention. Estimated life expectancy was derived from patient age, renal function and preexisting medical conditions. Statistical Methods Nonurologists, residents, fellows and those who reported that they evaluate 0 newly diagnosed renal tumors per Patient 1 Patient 2 Patient 3 Age (years) Creatinine (mg/dl or umol/l) 0.8 or or or 140 GFR (ml/min) 10 year life expectancy year were excluded from analyses. Survey responses were summarized with frequencies and percentages. For analysis each case was deconstructed into components (ie tumor size, depth and location). Respondents evaluated 8 cases and 3 index patients for a total of 24 case-patient combinations. Among those who chose PN or RN we determined the associations between predictor variables and choice of treatment via logistic regression with generalized estimating equations to adjust standard errors for repeated data within each respondent. Using the same analytic method we determined the association between predictor variables and the choice of AS vs any treatment (ablation, PN or RN). For each of these analyses we included urologist factors (eg fellowship training), patient factors (eg comorbidities) and case factors (eg tumor size). Unadjusted and adjusted odds ratios and 95% CI were calculated. Adjusted associations were derived from models that included all factors of interest simultaneously, with p 0.05 considered statistically significant. RESULTS Of 14,749 AUA members 4,513 (31%) had registered addresses and were invited to participate in the study. Of these members 866 (19%) completed the survey and 759 were included in the analysis (fig. 2). The majority of respondents were from North America with proportional age group representation and varied practice settings (table 1). Most respondents had not completed a post-residency fellowship in oncology or MIS. The majority of respondents performed a wide array of open and minimally invasive procedures (table 2). In addition, almost all urologists (676, 89%) recommended AS for select patients. Most participants (474, 62%) evaluated more than 10 patients with SRMs annually. Preoperative renal function assessment of patients with SRMs varied among urologists (table 3). More than half % 60% 30% Figure 1. Example case and 3 index patients from AUA small renal mass survey. Case was presented and analyzed as 2 cm, approximately mesophytic lower pole tumor.

3 SMALL RENAL MASS SURVEY 409 AUA Members (N=14,749) ed (n=4,513) Responded (n=866) Excluded: Fellows (n=11); Residents (n=70); Non-urologists (n=21) Staff/Attending Urologists (n=764) Excluded: Urologists that do not evaluate patients with renal tumors (n=5) Included in Analyses (n=759) Figure 2. Survey enrollment (486, 63%) of urologists occasionally obtain a renal biopsy. However, few routinely use this diagnostic test (45, 8% perform on more than 20% of patients with SRMs). For the respondents who occasionally obtain renal tumor biopsies, several factors influenced the decision to biopsy, including suspicion of nonrcc malignancy and patient comorbidity. From the general opinion questions solitary kidney (745, 99%), tumor location (666, 88%), hereditary RCC syndromes (656, 87%) and preoperative renal function (657, 87%) were most important when deciding between PN and RN (fig. 3, A). When choosing AS instead of definitive treatment patient comorbidity (679, 90%), patient age (650, 86%) and tumor size (644, 86%) were considered important by the majority of respondents (fig. 3, B). Responses for the 3 clinical cases were representative of the overall effects of patient and tumor factors on preferred management (fig. 4). Less than 5% of urologists chose RN for a 2 cm mesophytic lower pole tumor. However, many urologists chose RN for a 2 or 4 cm perihilar tumor. Based on overall responses to the 24 patient-case examples several factors were strongly associated with choosing RN over PN. On multivariable analyses tumor size (OR 8.4; 95% CI 7.1, 10.1 for 4 vs 2 cm; p ), tumor depth (OR 19.2; 95% CI 14.8, 25.0 for endophytic vs mesophytic; p ) and tumor location (OR 24.0; 95% CI 18.1, 31.8 for perihilar vs mid kidney; p ) were markedly associated with the preference for RN instead of PN. RN was less commonly chosen for a 68-year-old patient with moderate

4 410 SMALL RENAL MASS SURVEY Table 1. Characteristics of urologists who completed the AUA small renal mass survey No. (%) Age: 40 Yrs or younger 193 (25.4) (31.2) (30.8) Older than (12.5) Practice location: Missing 6 (0.8) North America 556 (73.8) Europe 64 (8.5) Central/South America 59 (7.8) Asia 59 (7.8) Australia 5 (0.7) Africa 10 (1.3) Practice setting: Missing 1 (0.1) Academic hospital 307 (40.5) Community hospital 298 (39.3) Community (individual practice) 150 (19.8) Other 3 (0.4) Yrs in practice: Missing 3 (0.4) 5 or Less 142 (18.8) (14.9) (15.1) (13.6) Greater than (37.6) Post-residency fellowship: Missing 1 (0.1) No 534 (70.4) Oncology 108 (14.2) MIS 83 (10.9) Combined oncology/mis 33 (4.4) renal insufficiency (OR 0.6; 95% CI 0.5, 0.7 for GFR 27 vs 60 ml/minute/1.73 m 2 ;p ). Fellowship trained urologists (OR 0.4; 95% CI 0.2, 0.6; p ) and urologists at academic hospitals (OR 0.6; 95% CI 0.4, 0.9; p 0.02) were less likely to choose RN. Urologists who evaluate a larger number of patients with SRMs tended to choose RN less often. However, this association was not statistically significant after adjusting for all other factors of interest (data not shown). Patient age, urologist age and geographic location did not significantly influence the preference for RN vs PN (data not shown). Table 3. Routine evaluation of renal function plus cross-sectional imaging and factors influencing the decision to perform SRM biopsy No. (%) Renal function test routinely used by 759 urologists: Serum creatinine 700 (92) Estimated GFR (ie Modification of Diet in Renal Disease) 303 (40) Renal scintigraphy (ie dimenapto-succinic acid) 218 (29) 24-Hr urine creatinine clearance 103 (14) Radionucleotide urine or plasma clearance (ie lothalamate) 90 (12) Reasons for performing renal tumor biopsy of 486 urologists: Suspicion of nonrcc malignancy 470 (97) Significant medical comorbidity 409 (84) Pt age 312 (64) Bilat renal tumors 298 (61) Multiple renal tumors 261 (54) Plan for AS 261 (54) Tumor size 156 (32) Tumor location 149 (31) Several factors were also associated with the preference for AS on multivariable analyses. Respondents were more likely to choose AS (compared to any treatment) in an older patient (OR 2.7; 95% CI 2.1, 3.6; p ) or in a patient with comorbidities including renal dysfunction (OR 10.0; 95% CI 8.0, 12.4; p ). In addition, urologists were less likely to choose AS of a 4 cm tumor compared to a 2 cm tumor (OR 0.18; 95% CI 0.15, 0.21; p ). Interestingly, AS was chosen more often if the tumor was perihilar compared to mid kidney (OR 2.0; 95% CI 1.8, 2.3; p ) or polar (OR 2.1; 95% CI 1.9, 2.5; p ). Urologists who practiced in the United States or Canada were more likely to choose AS (OR 1.6; 95% CI 1.2, 2.3; p 0.005). However, fellowship training, academic practice, urologist age and number of SRMs assessed per year were not associated with preference for AS (data not shown). DISCUSSION The increasing incidence of SRMs is partially explained by the ubiquitous use of cross-sectional abdominal imaging for unrelated conditions. Tradi- Table 2. Renal procedures performed annually by respondents 0 (%) 1 5 (%) 6 10 (%) (%) Greater Than 20 (%) RN: Open 86 (12) 391 (53) 141 (19) 84 (11) 39 (5) Laparoscopic 209 (30) 179 (26) 127 (18) 106 (15) 67 (10) PN: Open 126 (18) 387 (54) 106 (15) 60 (8) 34 (5) Laparoscopic 340 (52) 153 (23) 73 (11) 56 (9) 35 (5) Laparoscopic thermal ablation 417 (64) 161 (25) 46 (7) 22 (3) 6 (1) Includes all size renal masses.

5 SMALL RENAL MASS SURVEY 411 A PARTIAL NEPHRECTOMY vs. RADICAL NEPHRECTOMY B ACTIVE SURVEILLENCE vs. TREATMENT % OF RESPONDENTS % OF RESPONDENTS Not Important Neutral Important 0 Solitary Kidney Tumor Location Hereditary Renal Function Tumor Size Comorbidity Patient Age 0 Comorbidity Patient Age Tumor Size Tumor Growth Solitary Kidney Renal Function Tumor Biopsy Results Tumor Location Legal Issues Previous Surgery Figure 3. A, importance of factors when deciding between partial and radical nephrectomy. B, importance of factors when deciding between AS and treatment (thermal ablation, PN or RN). PREFERRED TREATMENT (%) 100 Surveillance Ablation Partial Nephrectomy Radical Nephrectomy YEAR OLD HEALTHY 2cm Renal Pole 2cm Peri-hilar 4cm Peri-hilar 68 YEAR OLD HEALTHY 2cm Renal Pole 2cm Peri-hilar 4cm Peri-hilar CLINICAL CASES 68 YEAR OLD COMORBID DISEASE Figure 4. Responses to 3 cases that exemplify associations between patient/tumor characteristics and management preference. 2cm Renal Pole 2cm Peri-hilar 4cm Peri-hilar tional treatment of these patients was RN. However, PN has emerged as the preferred extirpative technique for most patients given equivalent cancer outcomes and improved long-term renal function. 2,3 Other nephron sparing options such as thermal ablation and AS have gained acceptance, and are used based on patient comorbidity or patient and physician preference. Thermal ablation can be considered for poor surgical candidates and, given the indolent nature of most SRMs, AS appears to be a safe alternative for well selected patients. Although all of these options can be considered, little is known regarding what patient and tumor factors are important to urologists when treating SRMs. In this survey of more than 700 practicing urologists considerable heterogeneity was observed in the preferred treatment of patients with a SRM and we identified several factors associated with surgeon treatment preferences. Observational studies have consistently revealed oncologic safety and improved renal function in patients treated with PN compared to RN. 2,3 In addition several groups have found an association among renal function preservation, reduced cardiovascular events and prolonged overall survival. 5,7 The AUA Guideline for Management of the Clinical Stage 1 Renal Mass states that PN is a standard of care for a healthy patient. RN should be discussed as an alternate standard of care if PN is not technically feasible as determined by the urological surgeon. 8 In this survey RN was infrequently chosen as the treatment of choice for patients with a tumor at the renal pole but was often chosen when the tumor was in a more technically challenging location. These findings suggest that urologists are aware of the importance of preserving renal function but believe PN is not possible or has an unacceptable risk of complications for clinical T1a lesions if the tumor is larger, more endophytic or more centrally located. As implied in the AUA guidelines, technical feasibility may vary depending on the training and experience of the surgeon. 8 In this survey urologists who had completed a post-residency fellowship or who practiced in an academic setting were more likely to choose PN. While tumor size and location undoubtedly influence PN difficulty, these factors are usually not prohibitive with adequate training or experience. 9,10

6 412 SMALL RENAL MASS SURVEY While the majority of cases presented in the survey were managed with extirpative or ablative therapy, a substantial number were considered for AS. Several institutions have reported SRM active surveillance series. However, the overall proportion of patients treated with AS remains unknown. The selected use of AS in elderly, medically unfit patients observed in this survey is consistent with series evaluating the safety of AS. 11 Interestingly tumor location also influenced urologist decisions. The current data suggest AS is frequently used, and is used more commonly in older patients, those with medical comorbidity, small tumor size and central location. Presumedly the association between tumor location and choice of AS is related to treatment associated risk rather than AS safety. Thus, a standardized classification system based on tumor size and location such as the R.E.N.A.L. Nephrometry scoring system should be considered when designing future trials evaluating treatment associated risk. 12 Preoperative evaluation of a patient with a SRM is not standardized and is a research priority. 8 This is especially true for the preoperative evaluation of renal function and the usefulness of renal biopsy. Accurate determination of renal function is imperative when evaluating patients for renal surgery, especially when considering RN. Common methods of assessing renal function include serum creatinine alone, serum creatinine based formulas, and renal or plasma clearance of endogenous or exogenous compounds. 13 The majority of survey respondents only use serum creatinine (92%) or calculate GFR based on serum creatinine concentration (40%). The limitations of serum creatinine are well established as 30% of elderly patients have renal insufficiency despite a normal serum creatinine concentration. 13 Renal function estimates are improved when serum creatinine based formulas are used. However, the most accurate formula is debated. 14,15 Few urologists use plasma or urine clearance to assess renal function. Despite the superior accuracy of plasma/ urine clearance, the cost and inconvenience of these investigations prohibit routine use. The role of percutaneous biopsy in the evaluation of SRMs remains controversial. 16 Despite significant advances in diagnostic accuracy, 17,18 few survey respondents recommend SRM biopsy. For those who biopsy several factors influenced their decision. Not surprisingly the majority of respondents considered biopsy of a SRM if there was suspicion of a nonrcc malignancy. However, other factors such as significant medical comorbidities, patient age and plan for AS were also considered important. This suggests that biopsy information may be incorporated in treatment recommendations to a patient with a SRM. At this time the role of SRM biopsy is yet to be defined, and further study and clinical guidelines are needed. While there was considerable representation from urologists of varied age, patient volume and practice setting, these data may not be representative of the entire AUA membership due to respondent bias. The only factor that we were able to assess for respondent bias was urologist age. Surprisingly there did not appear to be a significant bias toward a specific age demographic (data not shown). However, it is possible that urologists who responded to the survey were also more likely to have certain clinical practice preferences. While we cannot be certain we surmise that respondents were more likely to perform PN compared to nonrespondents. Therefore, these data may overestimate the use of PN. CONCLUSIONS The AUA small renal mass survey revealed considerable heterogeneity in the treatment of patients with clinical T1a tumors. Several factors may explain these differences as the use of RN and AS is independently associated with tumor, patient and urologist factors. While nephron sparing techniques are often selected for tumors at the renal pole, many urologists continue to select RN when tumors are larger or more centrally located. ACKNOWLEDGMENTS The survey was made possible by the collaboration and cooperation of the American Urological Association. REFERENCES 1. Go AS, Chertow GM, Fan D et al: Chronic kidney disease and the risks of death, cardiovascular events, and hospitalization. N Engl J Med 2004; 351: Uzzo RG and Novick AC: Nephron sparing surgery for renal tumors: indications, techniques and outcomes. J Urol 2001; 166: Lau WK, Blute ML, Weaver AL et al: Matched comparison of radical nephrectomy vs nephronsparing surgery in patients with unilateral renal cell carcinoma and a normal contralateral kidney. Mayo Clin Proc 2000; 75: Huang WC, Levey AS, Serio AM et al: Chronic kidney disease after nephrectomy in patients with renal cortical tumours: a retrospective cohort study. Lancet Oncol 2006; 7: Thompson RH, Boorjian SA, Lohse CM et al: Radical nephrectomy for pt1a renal masses may be associated with decreased overall survival compared with partial nephrectomy. J Urol 2008; 179: 468.

7 SMALL RENAL MASS SURVEY Baillargeon-Gagne S, Jeldres C, Lughezzani G et al: A comparative population-based analysis of the rate of partial vs radical nephrectomy for clinically localized renal cell carcinoma. BJU Int 105: Miller DC, Schonlau M, Litwin MS et al: Renal and cardiovascular morbidity after partial or radical nephrectomy. Cancer 2008; 112: Campbell SC, Novick AC, Belldegrun A et al: Guideline for management of the clinical T1 renal mass. J Urol 2009; 182: Lebed B, Jani SD, Kutikov A et al: Renal masses herniating into the hilum: technical considerations of the ball-valve phenomenon during nephron-sparing surgery. Urology 2010; 75: Chan DY and Marshall FF: Partial nephrectomy for centrally located tumors. Urology 1999; 54: Chawla SN, Crispen PL, Hanlon AL et al: The natural history of observed enhancing renal masses: meta-analysis and review of the world literature. J Urol 2006; 175: Kutikov A and Uzzo RG: The R.E.N.A.L. nephrometry score: a comprehensive standardized system for quantitating renal tumor size, location and depth. J Urol 2009; 182: Lane BR, Poggio ED, Herts BR et al: Renal function assessment in the era of chronic kidney disease: renewed emphasis on renal function centered patient care. J Urol 2009; 182: Lane BR, Demirjian S, Weight CJ et al: Performance of the chronic kidney disease-epidemiology study equations for estimating glomerular filtration rate before and after nephrectomy. J Urol 183: Kim HL, Shah SK, Tan W et al: Estimation and prediction of renal function in patients with renal tumor. J Urol 2009; 181: Lane BR, Samplaski MK, Herts BR et al: Renal mass biopsy a renaissance? J Urol 2008; 179: Wang R, Wolf JS Jr, Wood DP Jr et al: Accuracy of percutaneous core biopsy in management of small renal masses. Urology 2009; 73: Volpe A, Mattar K, Finelli A et al: Contemporary results of percutaneous biopsy of 100 small renal masses: a single center experience. J Urol 2008; 180: EDITORIAL COMMENTS By surveying the AUA membership these authors identify factors influencing the treatment of patients with SRMs. In summary, tumor size, depth and location were associated with a preference for RN over PN. Additionally, fellowship trained and academic urologists were less likely to choose RN, which indicates that the perception of feasibility of PN is influenced by training and/or experience. Furthermore, it seems the factors most impacting the perceived feasibility of PN are tumor depth and location. This was also observed in that the urologists surveyed were more likely to base their preference for AS on tumor location and depth when evaluating the same size mass. The goals of this study are timely and important. However, it is worth noting the study limitations and biases. There is a low response rate at approximately 5% of the AUA membership. The response rate from academicians (greater than 40%) is also overrepresented compared to the AUA membership and likely contributes to overestimation of the use of nephron sparing techniques. In terms of practice patterns the actual rate of use of nephron sparing procedures is not reflected in this survey, and implies that some providers are responding as they believe they should as opposed to how they truthfully use these options. 1 Additionally, it is disappointing that PN is offered when it is perceived to be technically simple based on tumor location and depth, while other methods are chosen for difficult cases. The published evidence suggests that PN is safe and oncologically sound regardless of tumor depth and location, and should be routinely offered as an option to appropriate patients with SRMs, even if choosing PN necessitates referral to another provider with more training or experience. 2 Finally, the survey highlights the increasing use of AS and improved methods to assess global renal function. While these findings are encouraging, there is room for improvement, and hopefully we will find these trends matched in practice patterns and real-life use. Nicholas G. Cost and Vitaly Margulis Department of Urology University of Texas Southwestern Medical Center at Dallas Dallas, Texas REFERENCES 1. Miller DC, Saigal CS, Banerjee M et al: Diffusion of surgical innovation among patients with kidney cancer. Cancer 2008; 112: Van Poppel H: Efficacy and safety of nephron-sparing surgery. Int J Urol 2010; 17: 314. Respondents in this study appear to be accepting of partial nephrectomy for SRMs, particularly if the mass is located peripherally. One wonders why actual patterns of care studies do not seem to agree. For example, using Surveillance, Epidemiology and End Results-Medicare data from 1997 to 2002, only 19% of patients with a 4 cm or smaller renal mass underwent partial nephrectomy. 1 Admittedly these data are somewhat dated but they do call into question whether the respondents practice what they preach. If urologists are actually performing radical nephrectomies for SRMs, it begs the question

8 414 SMALL RENAL MASS SURVEY whether this is an entirely bad thing. There is no debate that there are real advantages to nephron sparing surgery and that PN is now a standard of care for the treatment of small renal tumors. However, AUA guidelines mention other possible approaches as well, including active surveillance and radical nephrectomy (reference 8 in article). From a quality of care perspective PN in the hands of a surgeon who rarely performs the procedure may result in significantly worse outcomes than the simpler radical nephrectomy in the same provider s hands. While this certainly makes the case for regionalization of care to selected centers of excellence in nephron sparing surgery, we must remember that these centers ultimately only have so much bandwidth and there is a real risk they could exceed their capacity quite quickly, resulting in delays in treatment and ultimately worse outcomes. To this end, radical nephrectomy (or, for that matter, active surveillance) may still be a reasonable approach in the management of SRMs and perhaps should not be dismissed so quickly. David F. Penson Vanderbilt University Nashville, Tennessee REFERENCE 1. Miller DC, Saigal CS, Banerjee M et al: Diffusion of surgical innovation among patients with kidney cancer. Cancer 2008; 112: REPLY BY AUTHORS We agree that there likely is a respondent bias in our survey. While we have no way of determining which direction the bias occurred, we suspect there was an overrepresentation from urologists who favor nephron sparing procedures. This suspicion is based on the observations that a disproportionate number of respondents were from academic centers and completed fellowships in oncology or MIS, and the preference for partial nephrectomy seemed to be higher than what we have noted in population based registries. However, most population based registries do not include recently treated patients, and it is not clear if practice patterns in 2002 apply to those in There have been a plethora of studies in the last 5 years highlighting favorable outcomes associated with partial nephrectomy, and we expect the impact of these findings will only be evident in contemporary practice. It is our hope that the survey responses represent a change of opinion in the urological community but only time will tell. In regard to radical nephrectomy for T1a renal tumors, we believe that indications for this procedure are becoming few. Partial nephrectomy for favorably located tumors should be part of the armamentarium of all urologists, and referral of difficult cases to high volume practices is appropriate. We agree that access to timely and quality care is important, which highlights the need for efficient referral pathways and continuing education programs to ensure that urologists are trained to safely perform renal surgery. However, in prior series delayed surgery for 6 months or longer in patients with T1a renal tumors was not associated with significant pathological up staging or change in treatment approach. We agree that ongoing population based assessment of benefit and harm is warranted.