Bilateral synchronous sporadic renal cell carcinoma: surgical management, oncological and functional outcomes

The current evidence on surgical management for synchronous bilateral renal tumors: results from a scoping review

PURPOSE

Synchronous bilateral renal masses (SBRM) account for a low percentage of kidney tumors, and there is no current recommendation for their management. The objective was to review evidence regarding the best surgical approach for SBRM in terms of type and timing of surgery.

METHODS

A broad literature search was performed on 28th January 2023 using Scopus, PubMed, and EMBASE. Only English papers dealing with adults were included. Meeting abstracts were excluded.

RESULTS

Twenty-four papers were accepted and included. SBRM behave less aggressively than metachronous tumors, and partial nephrectomy (PN) is the preferred therapeutic option to preserve renal function. Open, laparoscopic, and robot-assisted approaches were found to be similar in oncological outcomes, though robot-assisted surgery resulted in lower comorbidities. Same-sitting PN was demonstrated to be a safe approach, particularly in the robotic-assisted one. Finally, the same-siting and staged NSS were similar in preserving renal function.

CONCLUSIONS

PN should be the desirable treatment for SBRM whenever feasible and if patients are fit, but surgeon expertise should also be taken into the account.

Surgical Management of Synchronous, Bilateral Renal Masses: A 1-decade Referral Center Experience

BACKGROUND

Management and decision-making in patients with bilateral renal masses are controversial.

OBJECTIVE

To report our experience of surgical management in patients with bilateral renal masses undergoing surgery at a high-volume center.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively collected data from patients treated with partial nephrectomy (PN) or radical nephrectomy for bilateral renal masses at a single referral institution between June 2008 and June 2019. Patient- and tumor-related features, timing (one vs two stage), and surgical approach (open vs robotic) were analyzed.

SURGICAL PROCEDURE

A one- versus two-stage strategy was adopted according to the opportunity to perform at least one PN using a clampless or selective-clamping approach, in order to avoid acute kidney injury.

MEASUREMENTS

Operative time, warm ischemia time, and intra- and postoperative complications were recorded. Histopathological results and tumor histology were assessed.

RESULTS AND LIMITATIONS

Overall, 41 patients were included. The median age was 67 yr and the median preoperative estimated glomerular filtration rate (eGFR) was 84 ml/min/1.73 m². The median Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) score was 8 (interquartile range [IQR] 7-8) for both sides. In 17 (42%) patients, a simultaneous approach was chosen, with a pure robotic approach in 11/17 cases, while among the 24 (58.6%) patients treated with a two-stage strategy, 15 (62.5%) were treated with a robotic approach on both sides. Intraoperative complications and postoperative major (CDC ≥3) complications were recorded in 7.3% and 4.9% of cases, respectively. The overall positive surgical margins rate was 2.4%. At a median follow-up of 42 (IQR 18-59) mo, the median eGFR was 73 (IQR 64-80) ml/min/1.73 m², while disease-free survival and cancer-specific mortality were 90.2% and 7.3%, respectively.

CONCLUSIONS

Our experience underlines that both simultaneous and staged surgical treatment of patients with bilateral renal masses are feasible and safe if grounded on proper patient selection.

PATIENT SUMMARY

Management of patients with bilateral renal masses is challenging, given the heterogeneity of clinical scenarios and the need to optimize the timing of treatment to achieve maximal functional preservation while ensuring oncological efficacy.

Synchronous sporadic bilateral multiple chromophobe renal cell carcinoma accompanied by a clear cell carcinoma and a cyst: A case report

BACKGROUND

Renal cell carcinomas are usually unilateral. However, they are bilateral in 2% to 4% of sporadic cases and is considerably more common in familial cases. Synchronous sporadic bilateral multiple chromophobe renal cell carcinoma (CHRCC) with different subtypes is rare.

CASE SUMMARY

In this case report, we describe a case of synchronous bilateral CHRCC with two histological variants, accompanied by a clear cell carcinoma and a cyst in a 50-year-old male. The patient underwent retroperitoneal laparoscopic bilateral nephron-sparing surgery and there was no serious postoperative renal dysfunction.

CONCLUSION

We report a rare case of synchronous bilateral CHRCC with two histological variants associated with a clear cell carcinoma and a cyst.

Simultaneous versus staged partial nephrectomies for bilateral synchronous solid renal masses

OBJECTIVES

The optimal management approach for synchronous bilateral renal masses is unknown, particularly regarding surgical sequencing of bilateral partial nephrectomy (PN). We evaluated the impact of simultaneous vs. staged bilateral PN on renal functional, perioperative, and oncologic outcomes.

PATIENTS AND METHODS

We reviewed our institutional nephrectomy registry to identify patients who underwent simultaneous or staged (within 6 months) bilateral PN for nonmetastatic bilateral synchronous solid renal masses between 1980 and 2015. Short-term and long-term renal function changes were assessed at 3 and 12 months, respectively. Perioperative outcomes were pooled across staged surgeries by taking the sum of each outcome. Local recurrence-free, distant metastases-free, cancer-specific, and overall survival were estimated using the Kaplan-Meier method. Outcomes were compared by surgical sequencing approach. A sensitivity analysis was performed that grouped approaches by preoperative intent.

RESULTS

Among the 107 patients studied, 77 (72%) underwent simultaneous and 30 (28%) underwent staged PN. The majority of PN were performed by open approach. Clinicopathologic features were similar between groups. Patients who underwent simultaneous PN had lower mean short-term (-6% vs. -24%, P = 0.015) and median long-term (-4% vs. -22%, P < 0.001) reduction in eGFR vs. staged PN, respectively. Furthermore, patients with simultaneous PN had lower pooled length of stay (median 6 vs. 8 days, P < 0.001), rate of urine leak (3% vs. 17%, P = 0.018), and rate of high-grade complications (8% vs. 23%, P = 0.044), relative to staged PN, respectively. However, on sensitivity analysis, only differences in long term reduction in estimated glomerular filtration rate and length of stay remained. There were no significant differences in oncologic outcomes between groups.

CONCLUSIONS

Our results suggest that when technically feasible, simultaneous PN yields comparable outcomes vs. staged PN, offering a reasonable surgical sequencing approach for patients presenting with bilateral synchronous renal masses.

Synchronous Bilateral RCC Is Associated With Poor Recurrence-Free Survival Compared With Unilateral RCC: A Single-Center Study With Propensity Score Matching Analysis

BACKGROUND

Understanding the tumorigenesis of bilateral cancers occurring in paired organs is essential for treatment planning and follow-up strategies. To the best of our knowledge, only a few studies compared the survival outcomes in patients with unilateral and bilateral renal cell carcinoma (RCC). We aimed to evaluate the survival outcomes of these patients after surgery and perform a further comparison of synchronous and metachronous bilateral RCCs.

MATERIALS AND METHODS

We analyzed clinical data from a total of 2169 patients (98.0%) diagnosed with unilateral RCC and 44 patients (2.0%) diagnosed with bilateral RCC including 22 (50.0%) with synchronous (diagnosed concomitantly or within 3 months of the former tumor) and 22 (50.0%) with metachronous RCC at our institution. Comparative analysis of unilateral and bilateral RCC groups was conducted using propensity score matching analysis. Subgroup analysis of bilateral RCC including synchronous and metachronous RCCs was also performed.

RESULTS

Kaplan-Meier survival analysis showed a significantly decreased 5-year recurrence-free survival (RFS; 82.6% vs. 94.3%; log rank test, P = .045) in the bilateral RCC group compared with the unilateral group. In subgroup analysis, the metachronous RCC group showed significantly smaller mean pathologic tumor size (P = .011), and more favorable pathologic T stage (P = .036) compared with the synchronous RCC group. Kaplan-Meier survival analysis showed significantly decreased 5-year RFS in synchronous RCC compared with metachronous RCC (74.7% vs. 92.9%; log rank test, P = .028).

CONCLUSION

The bilateral RCC group showed significantly decreased 5-year RFS compared with the unilateral RCC group. Importantly, the synchronous RCC group manifested more adverse features than the metachronous group.

Multiple and Bilateral Sporadic Renal Cell Carcinomas: A Surgical Challenge

Sporadic, synchronous, bilateral, or unilateral Renal Cell Carcinomas constitute a rare clinical entity. We report the case of a 68-year-old male patient who presented in our department due to incidentally discovered multiple, bilateral renal tumors. Magnetic Resonance Imaging demonstrated cT1b renal tumors at the lower pole of each kidney and a cT1a renal tumor at the upper pole of the right kidney. The patient underwent transperitoneal, laparoscopic left partial nephrectomy with renal artery occlusion, histology revealed high-grade, pT1b, clear-cell renal cell carcinoma; however we observed decline of patient's estimated glomerular filtration rate postoperatively. Forty days postoperatively, he underwent open partial nephrectomy for the right sided tumors with manual compression of the renal parenchyma and no use of ischemia. Histology revealed high-grade, pT1a, clear-cell renal cell carcinoma at the upper pole of the right kidney and low-grade, pT1b, clear-cell renal cell carcinoma at the lower pole of the right kidney. There was no additional decline in the serum creatinine value postoperatively. The patient avoided permanent or temporary dialysis and 6 months postoperatively he demonstrated no recurrence on imaging and his renal function remained stable.

Outcomes of synchronous and metachronous bilateral small renal masses (< 4 cm): a population-based cohort study

OBJECTIVES

To report longitudinal outcomes of a population-based cohort of patients diagnosed with bilateral small renal masses from a period of over 11 years.

PATIENTS AND METHODS

Consecutive patients diagnosed with bilateral small renal masses (synchronous or metachronous) of a defined geographical area were recorded in a large database (TUCAN database) between January 2005 and December 2016. Patients had a unique identifier number and followed during this period using an agreed upon protocol. Clinicopathological characteristics and outcomes of bilateral small renal masses on active surveillance were analysed and compared to propensity score-matched sporadic unilateral small renal masses. Data were analysed for renal mass growth rate, rate of intervention and development of metastatic disease and patient survival.

RESULTS

A total of 1060 patients were diagnosed with renal cancer, of which bilateral small renal masses accounted for 70 (6.6%) cases. Synchronous SRMs were observed in 63 patients, whereas metachronous lesions were found in seven patients during the study period. Metachronous lesion mean time to appearance was 62 ± 41 months (range 9-149 months). While most cases were sporadic, four were found to be hereditary. Growth rate of bilateral small renal masses did not differ from that of unilateral sporadic small renal masses. Similarly, there were no differences between the groups for rate of interventions and survival.

CONCLUSIONS

Progression, rate of metastases and survival for patients diagnosed with bilateral small renal masses are similar to those diagnosed with unilateral disease.

Assessing Time of Full Renal Recovery Following Minimally Invasive Partial Nephrectomy

OBJECTIVE

To assess renal function in the operated kidney at different time points post partial nephrectomy (PN) and establish the time in which optimal recovery occurs. Recovery of renal function post-PN has received significant attention. However, the optimal time to determine full recovery has not been clearly established.

MATERIALS AND METHODS

Renal function following minimally invasive (laparoscopic and robotic) PNs performed between 2002 and 2015 was reviewed. Patients included in this study had renal function assessed preoperatively as well as 3 days, 6-12 weeks, and 1 year post-PN, using a combination of estimated glomerular filtration rate (eGFR) from serum creatinine and relative renal uptake (RRU) from Tc99m-MAG3 renal scintigraphy. Together, eGFR and RRU provide the ipsilateral renal function (IRF) of the operated organ.

RESULTS

At 6-12 weeks postoperatively, percent preserved eGFR, RRU, and IRF (relative to preoperative baselines) were 92.1%, 83.3%, and 77.4% respectively. %IRF at 6-12 weeks was significantly improved from %IRF at 3 days postoperatively, but did not differ significantly from 1 year postoperatively. Furthermore, 89% of patients had RRU values at 6-12 weeks which differed by less than 5% from RRU values at 1 year.

CONCLUSION

Our data suggest that renal function recovery at 6-12 weeks was equivalent to long-term recovery at 1 year in the majority of post-PN patients. This has important implications for post-PN follow-up, particularly in assessing the functional outcomes utilizing novel minimally invasive PN strategies, as well as in planning staged procedures for bilateral synchronous renal masses.

Clinicopathologic Features and Prognosis of Sporadic Bilateral Renal Cell Carcinoma: A Series of 148 Cases

INTRODUCTION

The purpose of this study was to investigate the clinicopathologic features, treatment, and prognosis of sporadic bilateral renal cell carcinoma (RCC).

PATIENTS AND METHODS

A total of 148 patients with sporadic bilateral RCC treated in our center from June 1986 to December 2015 were included in this retrospective study. Their clinicopathologic features and treatments were evaluated. The survival and prognostic factors were assessed based on data from follow-up.

RESULTS

The median age was 54 years (range, 31-78 years). There were 88 patients with synchronous bilateral RCC and 60 with metachronous bilateral RCC. The median interval between bilateral tumors of metachronous bilateral RCC was 75.5 months. There was no significant difference in tumor size, nuclear grade, or T stage between metachronous tumors (P = .385, P = .544, and P = .263, respectively). Of 148 patients, 124 patients underwent bilateral surgery, 16 underwent unilateral surgery, and 8 patients did not undergo surgery. Of the 317 tumors with pathologic results, 297 (93.7%) were clear-cell subtype. A total of 136 (91.9%) patients were followed-up, and the median follow-up period was 77 months (range, 2-398 months). During follow-up, 38 (27.9%) patients died. The 5-year overall survival rate was 85.9%. The median survival time of patients with no surgery was 5 months. Older age (P = .001), bilateral nonoperative treatment (P < .001), higher T stage (P < .001), and multifocality (P = .02) were related to worse prognosis in multivariate analysis.

CONCLUSION

In metachronous bilateral RCC, the latter occurrence does not bear a significantly worse pathologic biology. The prognosis of sporadic bilateral RCC with no surgery is poor. The overall oncologic results of patients with sporadic bilateral RCC are comparable with that of patients with unilateral RCC.

Independent Tumor Origin in Two Cases of Synchronous Bilateral Clear Cell Renal Cell Carcinoma

Bilateral renal cell carcinomas (RCCs) pose a challenge for clinical treatment and management. Most bilateral RCCs are sporadic, and do not show a hereditary pattern indicative of VHL syndrome or other inherited cancers. The origin and evolution of these sporadic bilateral RCCs remains elusive. We obtained normal and tumor samples from two male patients suffering from early stage synchronous bilateral clear cell RCC (ccRCC), and analyzed genomic DNA using whole exome sequencing and bisulfite pyrosequencing. We detected distinct 3p loss of heterozygosity (LOH) in both tumors in each patient. Two tumors within the same patient harbored distinct driver mutations and different CpG hypermethylation sites in the VHL promoter. Moreover, tumors exhibit independent evolutionary trajectories. Therefore, distinct 3p LOH, combined with contingent driver gene mutations and independent VHL hypermethylation, led to independent tumor origin and parallel evolution of bilateral ccRCC in these two patients. Our results indicate that tumors in these two cases were not due to common germline oncogenic mutations. They were results of multiple de novo mutations in each kidney, rather than primary ccRCC with contralateral renal metastasis. Therefore, histopathologic and genetic profiling from single tumor specimen may underestimate the mutational burden and somatic heterogeneity of bilateral ccRCCs.

Bilateral renal cancers: oncological and functional outcomes

PURPOSE

The authors assessed the characteristics of bilateral renal cancers.

METHODS

From January 1995 to January 2015, 65 patients underwent surgery for bilateral renal cancers. Thirty-four of the patients had 36 synchronous tumors, while the remaining 29 had metachronous tumors. The mean age of the patients was 60 ± 11 years. There were 22 females and 43 males. In all cases, bilateral partial nephrectomies or unilateral nephrectomy and contralateral nephron-sparing surgery were performed.

RESULTS

The mean sizes of the synchronous tumors were 5.0 ± 2.7 and 4.7 ± 3.0 cm at the first and the second operations, respectively. The average diameters of the metachronous carcinomas were 6.6 ± 3.0 and 3.1 ± 1.6 cm at the initial and the second surgeries, respectively. Histologic concordance was 91.1 % in the synchronous and 96.5 % in the metachronous tumors. The mean postoperative creatinine levels increased by 116 %, while the GFR decreased by 44.8 % in synchronous tumors at the second operation. The mean postoperative creatinine levels increased by 42 %, while the GFR decreased by 30.4 % in metachronous carcinomas at the second operation. The mean follow-up time was 4.8 ± 3.7 years. During this period, distant metastases occurred in two patients with synchronous tumors and in six cases with metachronous tumors. Local recurrences were detected in one case of synchronous tumor and in four patients with metachronous carcinomas. The 5-year overall and tumor-specific survivals were 53 and 80 %, respectively.

CONCLUSIONS

In patients with bilateral renal carcinomas, the histologic concordance was 93.6 %. The bilateral partial nephrectomies or unilateral nephrectomy and contralateral resection provided acceptable oncological and functional outcomes.

Bilateral Synchronous Sporadic Renal Cell Carcinoma: Retroperitoneoscopic Strategies and Intermediate Outcomes of 60 Patients

OBJECTIVE

To evaluate the presentation, management, pathology, and functional and oncological outcomes of patients undergoing retroperitoneoscopic treatment of bilateral synchronous sporadic RCC at our institution.

METHODS

We retrospectively evaluated the records of 60 patients with bilateral synchronous sporadic RCC who underwent retroperitoneoscopic treatment at the General Hospital of People's Liberation Army from 2008 to 2014. The estimated glomerular filtration rate was calculated and compared among different surgical procedures. The overall survival and recurrence free survival were assessed based on information from recent follow-up.

RESULTS

Fifty-six patients underwent bilateral retroperitoneoscopic surgeries in staged procedures, and four patients underwent bilateral retroperitoneoscopic surgeries in simultaneous procedures. Among the former group of patients, 34 underwent bilateral partial nephrectomy, 12 underwent radical nephrectomy followed by partial nephrectomy, and 10 underwent partial nephrectomy followed by radical nephrectomy. Bilateral partial nephrectomy can better preserve renal function (p = 0.040) and the sequence of partial nephrectomy and radical nephrectomy did not affect functional outcomes (p = 0.790). One patient undergoing simultaneous procedures developed acute renal failure and required temporary hemodialysis. At 3 and 5 years, overall survival rates were 93.0% and 89.4%, and recurrence free survival rates were 90.5% and 81.6%. High nuclear grade (p = 0.014) was related to disease recurrence.

CONCLUSIONS

Staged bilateral partial nephrectomy was efficient in preserving renal function. The survival of patients with bilateral synchronous sporadic renal tumors was similar to that of patients with unilateral nonmetastatic tumors. Nuclear grade was an independent prognostic factor of disease recurrence.

Bilateral synchronous sporadic renal tumors: pathologic concordance and clinical implications

OBJECTIVE

To determine the pathologic concordance rates in patients with bilateral synchronous sporadic renal tumors (BSSRT) and to determine factors predictive of concordance.

METHODS

A retrospective chart review from 1985 to 2008 was completed with search criteria of all patients diagnosed with bilateral renal tumors. We included patients who had image-documented BSSRT or via reported history. We excluded patients with bilateral metachronous renal tumors, cystic renal masses, familial renal cell carcinoma (RCC) syndromes, urothelial cell carcinomas, and other variant histology. Univariate and multivariate analysis were conducted to assess for factors predictive of concordance.

RESULTS

We identified 297 patients eligible for analysis. RCC concordance was exhibited in 222 of 249 (89%) of patients. Benign tumor concordance, specifically oncocytoma, was found in 41 of 59 (71%) of patients. Factors such as age, gender, and tumor size on imaging did not have an association with concordance rates for bilateral RCC or bilateral oncocytoma. On multivariate analysis, multifocal tumors were associated with benign concordance (OR = 6.9, 95% CI = 1.6-29.2, P = .009).

CONCLUSION

Malignant and benign concordance rates are high for patients with BSSRT. Given the high concordance of RCC, the data support a management approach consisting of bilateral nephron-sparing surgery whenever possible. However, given the high concordance rate of oncocytoma in this population as well, less aggressive management (renal mass biopsy and surveillance) of the contralateral kidney may be considered after histologic confirmation of one side.

Surgical management of bilateral synchronous kidney tumors: functional and oncological outcomes

PURPOSE

We evaluated renal functional and oncological outcomes after sequential partial nephrectomy and radical nephrectomy in patients with bilateral synchronous kidney tumors.

MATERIALS AND METHODS

A total of 220 patients treated from June 1994 to July 2008 were included in the study. Estimated glomerular filtration rate, and overall, cancer specific and recurrence-free survival were assessed.

RESULTS

Patients underwent sequential partial nephrectomy (134), partial nephrectomy followed by radical nephrectomy (60) or radical nephrectomy followed by partial nephrectomy (26). Final estimated glomerular filtration rate after bilateral surgery was 59, 36 and 35 ml/minute/1.73 m(2) in these 3 groups, respectively (p <0.001). The order in which partial nephrectomy and radical nephrectomy were conducted did not affect functional outcomes. Overall survival of patients with bilateral cancer was 86% at 5 years and 71% at 10 years, cancer specific survival was 96% at 5 and 10 years, and recurrence-free survival was 73% at 5 years and 44% at 10 years. Overall survival was decreased in patients with tumors larger than 7 cm (p = 0.003). Patients with postoperative stage III or greater chronic kidney disease had decreased overall survival due to noncancer causes (p = 0.007).

CONCLUSIONS

Patients treated with sequential surgery for bilateral synchronous kidney tumors have 5 and 10-year oncological outcomes comparable to those of patients with unilateral kidney cancer. Decreased overall survival was significantly associated with tumor size larger than 7 cm and postoperative stage III or greater chronic kidney disease. Nephron sparing surgery should be conducted for all amenable bilateral kidney masses given the negative impact of renal functional decline on overall survival.

Developments in the surgical management of sporadic synchronous bilateral renal tumours

OBJECTIVE

To examine our experience with managing sporadic bilateral renal masses, focusing on trends in surgical management over time, because as loss of renal function is associated with adverse cardiovascular outcomes, nephron-sparing approaches are increasingly emphasized in the treatment of kidney tumours, creating new challenges for the treatment of bilateral tumours.

PATIENTS AND METHODS

We identified all patients who underwent partial or radical nephrectomy (PN or RN) at Memorial Sloan-Kettering Cancer Center (MSKCC) during 1989-2008. We compared patients presenting with synchronous bilateral renal masses with those with unilateral tumour and evaluated trends in management using logistic regression.

RESULTS

Of the 2777 patients studied, 73 (3%) presented with synchronous bilateral disease. The overall survival and clinical/pathological features between groups were similar. Of those patients receiving bilateral operations for synchronous tumours, three had bilateral RN (all before 2003), 28 (38%) had an RN followed by a PN, 10 (14%) had a PN then an RN, and 32 (44%) had bilateral PN. Over time, the proportion of patients receiving bilateral PN increased (P < 0.001); 13 of 14 patients after 2005 had bilateral PN, compared with only 34% (16 of 45) between 1995 and 2004. Forty-five patients (62%) had the larger tumour removed during the first operation. The concordance rate between tumours in a specific histological subtype was 70% (51/73), and concordance for benign vs malignant disease was 90% (66/73).

CONCLUSION

The use of PN in the management of synchronous bilateral renal masses has increased over time. The contemporary treatment of synchronous bilateral renal masses at MSKCC involves staged PN when feasible, with the more involved kidney (often larger tumour) operated on first.

Long-term survival in bilateral renal cell carcinoma: a retrospective single-institutional analysis of 101 patients after surgical treatment

OBJECTIVES

Bilateral renal cell carcinomas (bRCC) account for <4% of all renal tumors. We report on the management, histopathologic results, and long-term follow-up of 101 patients with bRCC.

METHODS

A total of 101 patients with bRCC who had undergone surgery from 1975 to 2005 at our institution were identified from our kidney tumor database and included in this retrospective analysis. Cancer-specific survival was assessed using the Kaplan-Meier method. Subgroups were compared using the log-rank test. Statistical analysis was performed with the Statistical Package for Social Sciences for Windows.

RESULTS

Of 3097 kidney tumor patients, 101 (3.3%) had bRCC on final histopathologic examination. Synchronous tumors were found in 43 patients (42.6%) and metachronous tumors in 58 (57.4%). The cancer-specific survival rate of the entire cohort was 91.9%, 79.1%, and 56.7% after 5, 10, and 20 years, respectively. The survival of patients with synchronous or metachronous bRCCs did not differ significantly. Patients with metachronous bRCC were significantly younger at first diagnosis than those with synchronous bRCCs (median age 53.6 vs 58.7 years, P < .05). The histopathologic results revealed significantly greater rates of papillary bRCCs in synchronous tumors (P < .05).

CONCLUSIONS

Standardized techniques of nephron-sparing surgery can achieve excellent survival rates in bRCC. Among other arguments for nephron-sparing surgery, kidney-preserving strategies are of particular importance in younger patients with unilateral RCC against the background of an increasing risk of developing a contralateral neoplasm with older age.

The impact of temporal presentation on clinical and pathological outcomes for patients with sporadic bilateral renal masses

BACKGROUND

The origin of bilateral renal masses has not been definitively established to date. As limited studies on the genetics of bilateral tumors exist, defining the clinical behavior of these lesions remains important.

OBJECTIVE

To evaluate the impact of synchronous versus metachronous presentation on clinicopathological outcomes of patients with bilateral renal masses.

DESIGN, SETTING, AND PARTICIPANTS

We identified 310 patients who were treated at the Mayo Clinic for sporadic bilateral renal masses between 1970-2003, including 148 (47.7%) with synchronous tumors and 162 (52.3%) with metachronous lesions.

INTERVENTION

Patients underwent surgical resection of bilateral renal tumors.

MEASUREMENTS

Clinicopathological features of synchronous and metachronous tumors were compared. Survival rates for patients with synchronous (n=92) and metachronous (n=100) renal cell carcinoma (RCC) were estimated using the Kaplan-Meier method and compared with the log rank test.

RESULTS AND LIMITATIONS

Metachronous tumors had a greater degree of pathological concordance than synchronous lesions, with 87.7% of metachronous tumors representing bilateral RCC, compared to 69.2% of synchronous masses (p=0.002). Patients with synchronous RCC tended to have an increased incidence of papillary RCC compared to patients with metachronous RCC, who were more likely to have bilateral clear-cell RCC (p=0.076). A longer interval between tumors was inversely associated with the risk of cancer death for patients with metachronous RCC (HR 0.90, 95% CI 0.81-0.99, p=0.039). Compared to patients with metachronous RCC, patients with synchronous bilateral RCC had similar 10-yr CSS (70.5% vs. 69.4%, p=0.51) and OS (47.5% vs. 51.2%, p=0.58). We nevertheless recognize that these findings may be limited by the study's retrospective, single-institution design.

CONCLUSIONS

Metachronous bilateral solid renal masses have a greater degree of pathological concordance and were more likely to represent malignancy. Surgical resection may provide durable cancer control for patients with bilateral RCC, with no difference in survival noted between synchronous and metachronous cancers.