Node-positive renal cell carcinoma in the absence of distant metastases: predictors of cancer-specific mortality in a population-based cohort

Development and validation of a prognostic nomogram for predicting cancer-specific survival in patients with metastatic clear cell renal carcinoma: A study based on SEER database

Objectives

Clear cell renal cell carcinoma (ccRCC) is highly prevalent, prone to metastasis, and has a poor prognosis after metastasis. Therefore, this study aimed to develop a prognostic model to predict the individualized prognosis of patients with metastatic clear cell renal cell carcinoma (mccRCC).

Patients and Methods

Data of 1790 patients with mccRCC, registered from 2010 to 2015, were extracted from the Surveillance, Epidemiology and End Results (SEER) database. The included patients were randomly divided into a training set (n = 1253) and a validation set (n = 537) based on the ratio of 7:3. The univariate and multivariate Cox regression analyses were used to identify the important independent prognostic factors. A nomogram was then constructed to predict cancer specific survival (CSS). The performance of the nomogram was internally validated by using the concordance index (C-index), calibration plots, receiver operating characteristic curves, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA). We compared the nomogram with the TNM staging system. Kaplan–Meier survival analysis was applied to validate the application of the risk stratification system.

Results

Diagnostic age, T-stage, N-stage, bone metastases, brain metastases, liver metastases, lung metastases, chemotherapy, radiotherapy, surgery, and histological grade were identified as independent predictors of CSS. The C-index of training and validation sets are 0.707 and 0.650 respectively. In the training set, the AUC of CSS predicted by nomogram in patients with mccRCC at 1-, 3- and 5-years were 0.770, 0.758, and 0.757, respectively. And that in the validation set were 0.717, 0.700, and 0.700 respectively. Calibration plots also showed great prediction accuracy. Compared with the TNM staging system, NRI and IDI results showed that the predictive ability of the nomogram was greatly improved, and DCA showed that patients obtained clinical benefits. The risk stratification system can significantly distinguish the patients with different survival risks.

Conclusion

In this study, we developed and validated a nomogram to predict the CSS rate in patients with mccRCC. It showed consistent reliability and clinical applicability. Nomogram may assist clinicians in evaluating the risk factors of patients and formulating an optimal individualized treatment strategy.

Outcome after resection of occult and non-occult lymph node metastases at the time of nephrectomy

PURPOSE

There is sparse evidence on outcomes of resected occult LN metastases at the time of nephrectomy (synchronous disease). We sought to analyse a large international cohort of patients and to identify clinico-pathological predictors of long-term survival.

MATERIALS AND METHODS

We collected data of consecutive patients who underwent nephrectomy and LND for T_any cN0-1pN1 and cM0-1 RCC at 7 referral centres between 1988 and 2019. Patients were stratified into four clinico-pathological groups: (1) cN0cM0-pN1, (2) cN1cM0-pN1(limited, 1-3 positive nodes), (3) cN1cM0-pN1(extensive, > 3 positive nodes), and (4) cM1-pN1. Overall survival (OS) was estimated using the Kaplan-Meier method, and associations with all-cause mortality (ACM) were evaluated using Cox models with multiple imputations.

RESULTS

Of the 4370 patients with LND, 292 patients with pN1 disease were analysed. Median follow-up was 62 months, during which 171 patients died. Median OS was 21 months (95% CI 17-30 months) and the 5-year OS rate was 24% (95% CI 18-31%). Patients with cN0cM0-pN1 disease had a median OS of 57 months and a 5-year OS rate of 43%. 5-year OS (median OS) decreased to 29% (33 months) in cN1cM0-pN1(limited) and to 23% (23 months) in cN1cM0-pN1(extensive) patients. Those with cM1-pN1 disease had the worst prognosis, with a 5-year OS rate of 13% (9 months). On multivariable analysis, age (p = 0.034), tumour size (p = 0.02), grade (p = 0.02) and clinico-pathological group (p < 0.05) were significant predictors of ACM.

CONCLUSION

Depending on clinico-pathological group, grade and tumour size, 5-year survival of patients with LN metastases varies from 13 to 43%. Patients with resected occult lymph node involvement (cN0/pN1 cM0) have the best prognosis with a considerable chance of long-term survival.

To Be or "Node" to Be: Nodal Disease and the Role of Lymphadenectomy in the Treatment of Renal Cell Carcinoma

Lymph node involvement in renal cell carcinoma (RCC) correlates with poor oncologic outcomes. However, current RCC staging guidelines may not fully reflect the survival impact of lymph node positive disease. Recent data demonstrates that nodal disease has significant impact on survival and modifications to current staging guidelines have been proposed. Lymph node dissection (LND) at the time of surgical intervention for RCC remains controversial. While clinical trial data have demonstrated conflicting evidence for LND, some institutional studies suggests that carefully selected patients at high-risk for recurrence may benefit from LND. Prospectively, clinical trials are examining treating nodal disease and disease at high-risk of recurrence in the neoadjuvant and/or adjuvant setting at the time of nephrectomy. These promising trials are poised, if successful, to influence the treatment paradigm for localized RCC.

Reassessment of American Joint Committee on Cancer Staging for Stage III Renal Cell Carcinoma With Nodal Involvement: Propensity Score Matched Analyses of a Large Population-Based Study

Background: To assess the role of nodal involvement in stage III renal cell carcinoma (RCC) according to the American Joint Committee on Cancer (AJCC) 8th staging system. We compared the survival outcomes of RCC patients with pT1-3N1M0 disease and those with pT3N0M0 or stage IV (stratified as pT4NanyM0 and pTanyNanyM1) disease in a large population-based cohort. Methods: A cohort of 3,112 eligible patients with RCC was identified from the Surveillance, Epidemiology, and End Results (SEER) database, registered between January 2004 and December 2015. Kaplan-Meier and Cox proportional hazards models were used to evaluate the overall survival (OS), and cancer-specific survival (CSS). The prognostic value of the modified stage for pT1-3N1M0 disease was assessed by nomogram-based analyses. Propensity score matching (PSM) was used to adjust for potential baseline confounding. Results: Patients with pT1-3N1M0 disease showed similar survival outcomes (median OS 41.0 vs. 38.0 months, P = 0.77; CSS 45.0 vs. 39.0 months, P = 0.59) to pT4NanyM0 patients, whereas the significantly better survival outcome was found for pT3N0M0 patients. After PSM, comparable survival rates were observed between pT1-3N1M0 group and pT4NanyM0 group, which were still significantly worse than the survival of pT3N0M0 patients. The modified stage IIIA (pT3N0M0), IIIB (pT1-3N1M0, pT4NanyM0), and IV (pTanyNanyM1) showed higher predictive accuracy than AJCC stage system in the nomogram-based analyses (concordance index: 0.70 vs. 0.68, P < 0.001 for OS; 0.71 vs. 0.69, P < 0.001 for CSS). Conclusions: The pT1-3N1M0 RCC might be reclassified as stage IIIB together with pT4NanyM0 disease for better prediction of prognosis, further examination and validation are warranted.

Survival benefit with extended lymphadenectomy for advanced renal malignancy: A population-based analysis

Objective

We used population-based data to examine the possible benefit of extended lymphadenectomy for patients with renal malignancy in the setting of more advanced disease.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify non-metastatic, T3-T4 renal cancer patients from 2004–2015 treated with removal of ≥1 lymph node at the time of nephrectomy. Non-parametric bivariate statistics were used to assess associations between covariates of interest and extended lymphadenectomy (≥10 lymph nodes removed). Cancer-specific survival (CSS) and overall survival (OS) benefit was evaluated using Kaplan–Meier analysis.

Results

Of the 4397 patients identified, 816 (18.6%) underwent extended lymphadenectomy. For patients with T3a disease, 5-year CSS and OS benefit with extended lymphadenectomy did not reach statistical significance (CSS: hazard ratio [HR] 0.98, 95% confidence interval [CI] 0.77–1.24; OS: HR 0.96, 95% CI 0.77–1.20). Conversely, for those with T3b-T3c disease, extended lymphadenectomy led to statistically significant improvements in both 5-year CSS and OS compared to non-extended lymphadenectomy (CSS: HR 0.78, 95% CI 0.61–0.99; OS: HR 0.72, 95% CI 0.58–0.90). Finally, for those with T4 disease, use of extended lymphadenectomy had OS benefit after 5 years (OS: HR 0.51, HR 0.29–0.90, p = 0.02).

Conclusion

Based on population-level data, extended lymphadenectomy was associated with improved survival in select patients with advanced renal malignancy treated with surgical nephrectomy. Understanding the basis of these real-world findings in the face of conflicting randomized trial results will be key, moving forward.

Accuracy of clinical nodal staging and factors associated with receipt of lymph node dissection at the time of surgery for nonmetastatic renal cell carcinoma

INTRODUCTION

The benefit of lymph node dissection (LND) in renal cell carcinoma (RCC) remains poorly defined. Despite this uncertainty, the American Urological Association (AUA) guideline on localized renal cancer recommends that LND be performed for staging purposes when there is suspicion of regional lymphadenopathy on imaging. Using the National Cancer Database (NCDB), we sought to determine how much of a departure the new AUA guideline is from current practice. We hypothesized that practice patterns would reflect the "Expert Opinion" recommendation and that patients who are clinical lymph node (cLN) positive would receive a LND more often than those who are cLN negative. Additionally, we sought to determine factors that would trigger a LND as well the accuracy of clinical staging by examining the relationship between cLN and pathologic lymph node (pLN) status of patients who received a LND.

MATERIALS AND METHODS

The NCDB was queried for patients with nonmetastatic RCC who underwent partial nephrectomy or nephrectomy from 2010 to 2014. Patient sociodemographic and clinical characteristics were extracted. Frequency distributions were calculated for patients with both cLN and pLN status available. Of patients who received a LND, sensitivity, specificity, and positive/negative predictive values (PPV/NPV) of cLN status for pLN positivity were calculated. Logistic regression models were used to examine association between clinical and socioeconomic factors and receipt of LND. Propensity score matching was used in sensitivity analyses to examine potential for reporting bias in NCDB data.

RESULTS

We identified 110,963 patients who underwent surgery for RCC, of whom 11,867 (11%) had LND performed at the time of surgery. cLN and pLN information were available in 11,300 patients, of which 1,725 were preoperatively staged as having positive cLN. More LNDs were performed per year for patients who were cLN negative than cLN positive. Of patients who received a LND, the majority of patients were cLN negative across all clinical T (cT) stages. Multivariable analysis showed that all patients who had care at an academic/research institution (odds ratio [OR]: 1.58, 95% confidence interval [CI]: 1.43-1.74) and had to travel >12.5 to 31.0 miles and >31.0 miles to a treatment center (OR: 1.08, 95%CI: 1.01-1.15 and OR: 1.28, 95%CI: 1.20-1.36, respectively) were more likely to get a LND. As cT stage increased from cT2-4, the risk of LND increased (OR range: 4.7-7.90, respectively). Patients who were cLN positive were more likely to receive a LND at the time of surgery (OR: 18.68, 95%CI: 16.62-21.00). Of the patients who received a LND, clinical staging was more specific than sensitive.

CONCLUSION

More patients received a LND who were cLN negative compared to patients who were cLN positive. Patients who were cLN positive were more likely to receive a LND. Treatment center type, distance to treatment center, cT stage, and cLN positivity were factors associated with LND receipt.

The prognostic significance of nodal disease burden in patients with lymph node metastases from renal cell carcinoma

OBJECTIVES

To assess the relationship between nodal disease burden and overall survival (OS) among patients with lymph node (LN) metastases from renal cell carcinoma (RCC) METHODS: The National Cancer Data Base was used to identify 2,975 patients with RCC who were treated with radical nephrectomy and were found to have regional LN metastases. Associations between the number of positive and negative LN removed and OS were assessed using Cox proportional hazards regression. The median follow-up time among survivors was 3.6years.

RESULTS

The median number of positive LN was 1 (interquartile range 1-3). A higher number of positive LN was associated with higher all-cause mortality on multivariable analysis (HR 1.06 per 1 positive LN, 95% CI 1.04, 1.07, P < 0.001). Conversely, higher negative LN counts were associated with better OS (HR 0.97 per 1 negative LN, 95% CI 0.96, 0.99, P < 0.001). The adjusted probability of a patient with 1 LN removed that was positive surviving at least 2 years was 56%, a figure that increased to 64% when 1 out of 10 LN removed was positive and decreased to 38% when 10 out of 10 LN removed were positive.

CONCLUSIONS

Ours is the first study to show that differences in nodal disease burden translate into clinically significant differences in survival among patients with LN metastases from RCC.

Trends and outcomes of lymphadenectomy for nonmetastatic renal cell carcinoma: A propensity score-weighted analysis of the National Cancer Database

PURPOSE

Lymph node (LN) involvement in renal cell carcinoma (RCC) is associated with a poor prognosis. While lymph node dissection (LND) may provide diagnostic information, its therapeutic benefit remains controversial. Thus, the aim of our study is to analyze survival outcomes after LND for nonmetastatic RCC and to characterize contemporary practice patterns.

MATERIALS AND METHODS

The National Cancer Database was queried for patients with nonmetastatic RCC who underwent either partial or radical nephrectomy from 2010 to 2014. A total of 11,867 underwent surgery and LND. Chi-square tests were used to examine differences in patient demographics. To minimize selection bias, propensity score matching (PSM) was used to select one control for each LND case (n = 19,500). Cox regression analyses were conducted to examine overall survival (OS) in patients who received LND compared to those who did not.

RESULTS

Of all patients undergoing LND for RCC (n = 11,867), 5%, 23%, 31%, 47% were performed for tumors of clinical T stage 1, 2, 3, and 4, respectively. Proportions of LND have not significantly changed from 2010 to 2014. No significant improvement in median OS for patients undergoing LND compared to no LND was shown (34.7 vs. 34.9 months, respectively; P = 0.98). Similarly, no significant improvement in median OS was found for clinically LN positive patients undergoing LND compared to no LND (P = 0.90). On Cox regression analysis, LND dissection was not associated with an OS benefit (hazard ratio: 1.00; 95% confidence interval 0.97 to 1.04).

CONCLUSIONS

Among all RCC patients, LNDs are often performed for low stage disease, suggesting a potential overutilization of LND. No OS benefit was seen in any subgroup of patients undergoing LND. Further investigation is needed to determine which patient populations may benefit most from LND.

Renal cell carcinoma and pathologic nodal disease: Implications for American Joint Committee on Cancer staging

BACKGROUND

Lymph node (LN) metastases are associated with poor outcomes for patients with renal cell carcinoma (RCC). This study compared the survival outcomes of patients with stage III, node-positive disease (pT₁₂₃ N₁ M₀ ) and patients with stage III, node-negative disease (pT₃ N₀ M₀ ).

METHODS

A database of 4652 patients with RCC of any histological subtype treated with surgery at The University of Texas MD Anderson Cancer Center from 1993 to 2012 was retrospectively assessed. A total of 115 patients with pT₁₂₃ N₁ M₀ disease, 274 patients with pT₃ N₀ M₀ disease, and 523 patients with pT₁₂₃ N_0/x M₁ disease were included. Overall survival (OS) and cancer-specific survival (CSS) were estimated and compared between each cohort.

RESULTS

Median OS and CSS times were significantly better for pT₃ N₀ M₀ patients than pT₁₂₃ N₁ M₀ patients (OS, 10.2 vs 2.4 years, P < .0001; CSS, not reached vs 2.8 years, P < .0001). Similar median OS and CSS times were noted for pT₁₂₃ N₁ M₀ and pT₁₂₃ N_0/x M₁ patients (OS, 2.4 vs 2.4 years; P = .62; CSS, 2.8 vs 2.4 years; P = .10). In a multivariate analysis, tumor grade (hazard ratio [HR] for OS, 2.47; P < .0001; HR for CSS, 2.99; P < .0001) and pathologic LN involvement (HR for OS, 2.44; P < .0001; HR for CSS, 2.85; P < .0001) were associated with worse OS and CSS.

CONCLUSIONS

Among RCC patients classified with stage III disease, those with pT₁₂₃ N₁ M₀ disease had significantly worse survival than those with pT₃ N₀ M₀ disease. OS and CSS were similar for patients with pT₁₂₃ N₁ M₀ disease and patients with pT₁₂₃ N_0/x M₁ disease (stage IV). If validated, these findings suggest that RCC patients with nodal disease should be reclassified as having stage IV disease.

The contemporary role of lymph node dissection in the management of renal cell carcinoma

The appropriate role of lymph node dissection (LND) in the management of patients with renal cell carcinoma (RCC) is still a matter of debate. There is ample evidence that LND is the most accurate modality for staging the regional lymph nodes (LNs), which may harbor metastatic disease in greater than one-third of patients with high-risk RCC. The presence of LN metastases is an independent negative prognostic factor in this disease and accurate determination of LN status not only helps with patient counselling regarding prognosis and tailoring of postoperative surveillance schedules, but it also identifies patients at high risk of systemic disease recurrence who may qualify for clinical trials of adjuvant systemic therapies. Meanwhile, the therapeutic value of LND has been brought into question by a randomized trial (European Organisation for Research and Treatment of Cancer; EORTC 30881) that showed no difference in progression-free or overall survival between patients who were treated with radical nephrectomy (RN) and LND and those treated with RN alone. Given that most patients enrolled in this trial had small renal masses and therefore were at low risk for LN metastases, the question of whether patients with high-risk tumors derive a therapeutic benefit from a standardized, extended LND remains unanswered.

The role of lymph node dissection in the management of renal cell carcinoma: a systematic review and meta-analysis

Our objective was to evaluate the role of retroperitoneal lymph node dissection (LND) in non-metastatic (M0) and metastatic (M1) renal cell carcinoma (RCC). We searched Medline, EMBASE, Web of Science and Scopus from database inception to 29 August 2017 for studies of patients who underwent partial or radical nephrectomy for M0 or M1 RCC. Two investigators independently selected studies for inclusion. Risk of bias was assessed using the Newcastle-Ottawa scale, Cochrane Collaboration tool and National Heart, Lung and Blood Institute Quality Assessment Tool. Random effects meta-analysis was performed for all-cause-mortality. The GRADE approach was used to characterize quality of evidence. A total of 51 unique studies were included in the qualitative systematic review. Risk of bias was low in 41/51 (80%) studies. LND was not associated with all-cause mortality in either M0 (hazard ratio [HR] 1.02, 95% confidence interval [CI] 0.92-1.12; I² = 0%; four studies), M1 (HR 1.04, 95% CI 0.83-1.29; I² = 0%; two studies), or pooled M0 and M1 settings (HR 1.00, 95% CI 0.92-1.09; I² = 0%; seven studies), with no statistically significant differences according to M stage subgroups (P = 0.50). In the three studies that examined M0 subgroups with a high risk of nodal metastasis, LND was not associated with improved oncological outcomes. Studies on the association of extent of LND with survival reported inconsistent results. Meanwhile, a small proportion of patients with pN1M0 disease demonstrate durable long-term oncological control after surgery, with 10-year cancer-specific survival of 21-31%. Nodal involvement is independently associated with adverse prognosis in both M0 and M1 settings. GRADE quality of evidence was moderate or low for the outcomes examined. Although LND yields independent prognostic information, the existing literature does not support a therapeutic benefit to LND in either M0 or M1 RCC. High-risk M0 patient groups warrant further study, as a subset of patients with isolated nodal metastases experience long-term survival after surgical resection.

Indications, complications, and outcomes following surgical management of locally advanced and metastatic renal cell carcinoma

INTRODUCTION

Surgery may set the basis for a potential cure or would provide the best achievable quality of life in locally advanced or metastatic renal cell carcinoma (mRCC). However, survival extension with this approach would be scarce and not exempt from adverse events, thus preventing its recommendation in an already frail patient. An evidence based analysis on the role of surgery in each of the possible clinical scenarios involved under this heading may provide a clear picture on this issue and would be of value in the decision making process. Areas covered: Current literature was queried in PubMed/Medline in a systematic fashion. Manuscripts included were selected according to the quality of the data provided. A narrative review strategy was adopted to summarize the evidence acquired. Expert commentary: A surgery-based multimodal treatment approach should be strongly considered after adequate counseling in locally advanced and mRCC, since it may provide for additional benefits in terms of survival. However, a critical reevaluation of its adequacy, optimal timing, and selection of ideal candidates is currently ongoing.

Perioperative Morbidity of Lymph Node Dissection for Renal Cell Carcinoma: A Propensity Score-based Analysis

BACKGROUND

There are little data regarding the morbidity of lymph node dissection (LND) for renal cell carcinoma (RCC) to assess its risk-benefit ratio.

OBJECTIVE

To evaluate the association of LND with 30-d complications among patients undergoing radical nephrectomy (RN) for RCC.

DESIGN, SETTING, AND PARTICIPANTS

A total of 2066 patients underwent RN for M0 or M1 RCC between 1990 and 2010, of whom 774 (37%) underwent LND.

INTERVENTION

RN with or without LND.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Associations of LND with 30-d complications were examined using logistic regression with several propensity score techniques. Extended LND, defined as removal of ≥13 lymph nodes, was examined in a sensitivity analysis.

RESULTS AND LIMITATIONS

A total of 184 (9%) patients were pN1 and 302 (15%) were M1. Thirty-day complications occurred in 194 (9%) patients, including Clavien grade ≥3 complications in 81 (4%) patients. Clinicopathologic features were well balanced after propensity score adjustment. In the overall cohort, LND was not statistically significantly associated with Clavien grade ≥3 complications, although there was an approximately 40% increased risk of any Clavien grade complication that did not reach statistical significance. Likewise, LND was not significantly associated with any Clavien grade or Clavien grade ≥3 complications when separately evaluated among M0 or M1 patients. Extended LND was not significantly associated with any Clavien grade or Clavien grade ≥3 complications. LND was not associated with length of stay or estimated blood loss. Limitations include a retrospective design.

CONCLUSIONS

LND is not significantly associated with an increased risk of Clavien grade ≥3 complications, although it may be associated with a modestly increased risk of minor complications. In the absence of increased morbidity, LND may be justified in a predominantly staging role in the management of RCC.

PATIENT SUMMARY

Lymph node dissection for renal cell carcinoma is not associated with increased rates of major complications.

Surgical Management of Advanced and Metastatic Renal Cell Carcinoma: A Multidisciplinary Approach

The past decade has seen a rapid proliferation in the number and types of systemic therapies available for renal cell carcinoma. However, surgery remains an integral component of the therapeutic armamentarium for advanced and metastatic kidney cancer. Cytoreductive surgery followed by adjuvant cytokine-based immunotherapy (predominantly high-dose interleukin 2) has largely given way to systemic-targeted therapies. Metastasectomy also has a role in carefully selected patients. Additionally, neoadjuvant systemic therapy may increase the feasibility of resecting the primary tumor, which may be beneficial for patients with locally advanced or metastatic disease. Several prospective trials examining the role of adjuvant therapy are underway. Lastly, the first immune checkpoint inhibitor was approved for metastatic renal cell carcinoma (mRCC) in 2015, providing a new treatment mechanism and new opportunities for combining systemic therapy with surgery. This review discusses current and historical literature regarding the surgical management of patients with advanced and mRCC and explores approaches for optimizing patient selection.

Renal Cell Carcinoma with Isolated Lymph Node Involvement: Long-term Natural History and Predictors of Oncologic Outcomes Following Surgical Resection

BACKGROUND

Renal cell carcinoma (RCC) with isolated lymph node (LN) involvement has historically been associated with poor prognosis. However, a subset of patients may experience long-term survival.

OBJECTIVE

To examine the natural history of RCC with isolated LN involvement following surgical resection with long-term follow-up, and to evaluate clinicopathologic features associated with disease progression and survival.

DESIGN, SETTING, AND PARTICIPANTS

A total of 138 patients with isolated pN1M0 RCC underwent partial or radical nephrectomy and LN dissection from 1980 to 2010.

INTERVENTION

Partial or radical nephrectomy with LN dissection.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival (OS) were estimated using the Kaplan-Meier method. Associations between clinicopathologic features and oncologic outcomes were evaluated using Cox regression models.

RESULTS AND LIMITATIONS

Median follow-up among survivors was 8.5 yr. The 5-yr and 10-yr MFS, CSS, and OS rates were 16% and 15%, 26% and 21%, and 25% and 15%, respectively. The median time to development of metastases was only 4.2 mo. On multivariable analysis, symptoms at presentation (hazard ratio [HR] 2.40; p=0.03), inferior vena cava tumor thrombus (HR 1.99; p=0.003), clear cell (HR 2.21; p=0.01) and collecting duct/not otherwise specified (HR 4.28; p<0.001) histologic subtypes, pT4 stage (HR 2.64; p=0.005), and coagulative tumor necrosis (HR 2.51; p<0.001) were independently associated with development of metastases. MFS rates at 1 yr after surgery were 71%, 63%, 33%, and 7% for patients with one, two, three, and four to five adverse features, respectively. Limitations include surgical selection bias.

CONCLUSIONS

Although isolated pN1 disease portends a poor prognosis, a small subset of patients experience durable long-term survival after surgical resection of isolated lymphatic metastases. Adverse prognostic features may enhance patient risk stratification and facilitate multimodal management approaches.

PATIENT SUMMARY

Although isolated lymph node metastases portend a poor prognosis, a small subset of patients experience long-term survival following surgical resection.

Preoperative predictors of pathological lymph node metastasis in patients with renal cell carcinoma undergoing retroperitoneal lymph node dissection

PURPOSE

Patients with locally advanced renal cell carcinoma represent a subset that may benefit from retroperitoneal lymph node dissection. We identified preoperative clinical predictors of positive lymph nodes in patients with renal cell carcinoma without distant metastasis who underwent retroperitoneal lymph node dissection.

MATERIALS AND METHODS

We retrospectively analyzed data on a consecutive cohort of 1,270 patients with cTany Nany M0 renal cell carcinoma who were treated at a single institution from 1993 to 2012. Multivariate analysis was performed to determine preoperative predictors of pathologically positive lymph nodes in patients who underwent retroperitoneal lymph node dissection. A nomogram was developed to predict the probability of lymph node metastasis. Overall, cancer specific and recurrence-free survival was estimated using the Kaplan-Meier Method.

RESULTS

We identified 1,270 patients with renal cell carcinoma without distant metastasis who had (564) or did not have (706) retroperitoneal lymph node dissection performed. Of the 564 patients 131 (23%) and 433 (77%) had pN1 and pN0 disease, and 60 (37%) and 29 (7.2%) had cN1pN0 and cN0pN1 disease, respectively. ECOG PS, cN stage, local symptoms and lactate dehydrogenase were associated with nodal metastasis on multivariable analysis. A nomogram was developed with a C-index of 0.89 that demonstrated excellent calibration. Differences in overall, cancer specific and recurrence-free survival among pNx, pN0 and pN1 cases were statistically significant (p <0.001).

CONCLUSIONS

Local symptoms, ECOG PS, cN stage and lactate dehydrogenase were independent predictors of lymph node metastasis in patients who underwent retroperitoneal lymph node dissection. Our predictive nomogram using these factors showed excellent discrimination and calibration.

Extent of lymphadenectomy does not improve the survival of patients with renal cell carcinoma and nodal metastases: biases associated with the handling of missing data

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: A recent population-based analysis suggested a potential survival benefit with respect to performing lymph node dissection at nephrectomy in node-positive patients with RCC. The findings of the present study failed to corroborate the association of a survival benefit with the performance of lymph node dissection at nephrectomy.

OBJECTIVE

Previous studies showed no survival benefit with respect to performing lymph node dissection (LND) at nephrectomy, whereas a recent population-based analysis suggested otherwise, although the latter relied on imputation. To reconcile the findings of that study by critically evaluating the handling of missing data.

PATIENTS AND METHODS

Study participants comprised patients diagnosed with non-metastatic renal cell carcinoma (RCC) of all stages who underwent LND at nephrectomy (n = 10 596). Multivariable Cox regression models were performed to predict cancer-specific mortality (CSM), where the primary variable of interest was the extent of LND. To examine differences in approaches with respect to handling missing data, separate analyses were performed: (i) imputed population; (ii) exclusion of patients with missing data; and (iii) inclusion of patients with missing data as a sub-category.

RESULTS

Overall, 2916 (28%) patients had missing tumour grade. In multivariable analyses, our findings showed that increasing the extent of LND was associated with a significant protective effect on CSM in patients with pN1 after imputation (hazard ratio [HR], 0.82; P = 0.04). By contrast, the extent of LND was no longer significantly associated with a lower risk of CSM after excluding patients with a missing tumour grade (HR, 0.83; P = 0.1) or when including patients with missing tumour grade as a sub-category (HR, 0.82; P = 0.05).

CONCLUSIONS

The findings of the present study failed to corroborate the association of a survival benefit with increasing extent of LND at nephrectomy. The different methodologies employed to account for missing data may introduce important biases. Such considerations are non-negligible with respect to the interpretation of results for investigators who rely on administrative cohorts.