Relevance of extracapsular extension of pelvic lymph node metastasis in patients with bladder cancer treated in the contemporary era

Prognostic Significance of Lymph Node Density in Pathological Node Positive Urothelial Carcinoma of the Bladder -Upfront Surgery and Post Neoadjuvant Chemotherapy Cohorts

AIM

To validate the role of lymph node density as a prognostic marker in patients undergoing primary surgery and postneoadjuvant therapy in pathological node-positive urothelial bladder carcinoma.

MATERIALS AND METHODS

Retrospective analysis of 503 patients who underwent radical cystectomy from 2006 to 2019 for muscle-invasive urothelial bladder carcinoma, of which 152 patients with pathological node-positive disease were analyzed. Demographic details, pathological findings, treatment details, disease-free, and overall survival were documented. X tile program analysis was used to divide patients with positive lymph nodes into 3 groups: LD1: <= 7, LD2 :>7 to <15, LD3: >15, and the optimal cut-off value obtained was 15%. To evaluate the impact of lymph node ratio, patients with positive lymph nodes into 3 categories for each cut-off point estimation method, the application generates the histogram, Kaplan-Meier plot and calculates hazard ratio, confidence intervals and P-values. Univariate and multivariate cox regression analysis was done with a P-value of <.05, considered significant.

RESULTS

One hundred fifty-two patients (30.2%) had pathological nodal metastasis, with 87 of them having perinodal extension. Ninety-six underwent primary surgery, and 56 were postneoadjuvant chemotherapy. The median follow-up was 55.42 months. 68 of the 152 node-positive patients died of the disease. Median number of lymph nodes removed was 17.11. Lymph node density divided into tertiles were LD1 <7%, LD2 7-<15%, LD3 >15% showed 5-year RFS 40.5%,29.3%, 22.6% and 5 year OS was 55.5%, 42.4%,32.1% respectively. Cox regression analysis showed that age less than 55 years ,higher tumor stage, lymphovascular invasion, and higher lymph node ratio were significant in univariate and multivariate analysis. The lymph node density cut-off value of 15% was substantial among node-positive patients (P = .027), and subgroup analysis in upfront surgery with the adjuvant treatment group and postneoadjuvant chemotherapy group was also significant (P =.021).

CONCLUSION

Pathological higher T stage, Age <55 years, Lymphovascular invasion, adjuvant chemotherapy , adjuvant radiation treatment and lymph node density had prognostic significance in both cohorts of patients who underwent upfront surgery and neoadjuvant chemotherapy. Lymph node density cut-off value of <15% was prognostically significant.

Extranodal Extension Predicts Poor Survival Outcomes among Patients with Bladder Cancer

BACKGROUND

Several lymph node-related prognosticators were reported in bladder cancer patients with lymph node involvement and receiving radical cystectomy. However, extranodal extension (ENE) remained a debate to predict outcomes.

METHODS

A retrospective analysis of 1303 bladder cancer patients receiving radical cystectomy and bilateral pelvic lymph node dissection were identified in the National Taiwan Cancer Registry database from 2011 to 2017. Based on the 304 patients with lymph node involvement, the presence of ENE and major clinical information were recorded and calculated. The overall survival (OS) and cancer-specific survival (CSS) were estimated with Kaplan-Meier analysis and compared using the log-rank test. Hazard ratios (HR) and the associated 95% confidence intervals were calculated in the univariate and stepwise multivariable models.

RESULTS

In the multivariable analysis, ENE significantly reduced OS (HR = 1.74, 95% CI 1.09-2.78) and CSS (HR = 1.69, 95% CI 1.01-2.83) more than non-ENE. In contrast, adjuvant chemotherapy was significantly associated with better OS and CSS upon the identification of pathological nodal disease.

CONCLUSIONS

Reduced OS and CSS outcomes were observed in the pathological nodal bladder cancer patients with ENE compared with those without ENE. After the identification of pathological nodal disease, adjuvant chemotherapy was associated with better survival outcomes.

Lymph node density vs. the American Joint Committee on Cancer TNM nodal staging system in node-positive bladder cancer in patients undergoing extended or super-extended pelvic lymphadenectomy

PURPOSE

We compared the prognostic value of the American Joint Committee on Cancer (AJCC) TNM nodal staging system with that of lymph node (LN) density in patients with LN-positive bladder cancer who received extended or super-extended pelvic lymphadenectomy.

METHODS

Of the 1,018 patients, who underwent radical cystectomy and pelvic lymphadenectomy between February 2005 and August 2014, 110 patients with LN metastases with extended (n = 68) or super-extended (n = 42) pelvic lymphadenectomy were included. All patients were staged using the 2002 (sixth edition) and 2010 (seventh edition) AJCC TNM staging systems. The association of several variables with recurrence-free survival (RFS) and overall survival (OS) was evaluated.

RESULTS

The median number of total LNs removed was 29 (6-118) and the median LN density was 12.5% (1.6%-100%). RFS and OS were not significantly different between the 2002 (pN1-pM1) and 2010 (pN1-N3) AJCC TNM nodal staging systems (sixth edition: P = 0.512 and P = 0.519; seventh edition: P = 0.676 and P = 0.671, respectively). The 2-year RFS and OS rates according to the LN density quartiles were 58.5% and 76.9% in Q1, 39.1% and 70.8% in Q2, 28.8% and 50.1% in Q3, and 12.7% and 20.8% in Q4 (P = 0.001 and P = 0.001, respectively). Multivariate analysis adjusted for the 2010 AJCC TNM staging system showed that LN density was associated with a decreased OS (HR = 1.024; 95% CI: 1.010-1.039; P = 0.001). The nodal staging system (2002 or 2010) was not associated with the RFS and OS.

CONCLUSIONS

LN density shows a better prognostic value than the AJCC TNM nodal staging system in patients with LN-positive bladder cancer receiving extended or super-extended pelvic lymphadenectomy.

Extracapsular Extension of Pelvic Lymph Node Metastasis is an Independent Prognostic Factor in Bladder Cancer: A Systematic Review and Meta-analysis

PURPOSE

We aimed to elucidate the relation between extracapsular extension (ECE) and clinical outcomes in node-positive patients following radical cystectomy for bladder cancer.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched PubMed, SCOPUS, Web of Science, and Cochrane Library databases from their respective dates of inception until September 2014.

RESULTS

Ten articles that met the eligibility criteria included 43-748 subjects per study, with the total number of patients being 1,893. The frequency of ECE ranged from 36.6 to 58.1 %. The pooled hazard ratio (HR) was statistically significant for recurrence-free survival (RFS) [pooled HR 1.56; 95 % confidence interval (CI) 1.13-2.14] and cancer-specific survival (CSS) (pooled HR 1.60; 95 % CI 1.29-1.99) but not overall survival (OS) (pooled HR 1.47; 95 % CI 0.71-3.05). Heterogeneity in RFS (I (2) 84 %, p < 0.00001) and OS (I (2) 80 %, p = 0.03) was statistically significant. According to subgroup analysis with meta-regression analyses, "region" (pheterogeneity < 0.0001) and "analysis results" (pheterogeneity < 0.0001) were the sources of heterogeneity. Sensitivity analysis showed that omission of any study did not lead to a significant difference. No statistical evidence of publication bias regarding RFS or CSS was revealed among the studies using Begg's and Egger's tests.

CONCLUSIONS

This meta-analysis shows that ECE is an efficient prognostic factor for node-positive bladder cancer. However, large prospective studies are needed to confirm the clinical utility of ECE as an independent prognostic factor before these results can be applied clinically.

Extranodal extension is a powerful prognostic factor in bladder cancer patients with lymph node metastasis

BACKGROUND

Lymph node metastasis (LNM) is the most powerful pathologic predictor of disease recurrence after radical cystectomy (RC). However, the outcomes of patients with LNM are highly variable.

OBJECTIVE

To assess the prognostic value of extranodal extension (ENE) and other lymph node (LN) parameters.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective analysis of 748 patients with urothelial carcinoma of the bladder and LNM treated with RC and lymphadenectomy without neoadjuvant therapy at 10 European and North American centers (median follow-up: 27 mo).

INTERVENTION

All subjects underwent RC and bilateral pelvic lymphadenectomy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Each LNM was microscopically evaluated for the presence of ENE. The number of LNs removed, number of positive LNs, and LN density were recorded and calculated. Univariable and multivariable analyses addressed time to disease recurrence and cancer-specific mortality after RC.

RESULTS AND LIMITATIONS

A total of 375 patients (50.1%) had ENE. The median number of LNs removed, number of positive LNs, and LN density were 15, 2, and 15, respectively. The rate of ENE increased with advancing pT stage (p<0.001). In multivariable Cox regression analyses that adjusted for the effects of established clinicopathologic features and LN parameters, ENE was associated with disease recurrence (hazard ratio [HR]: 1.89; 95% confidence interval [CI], 1.55-2.31; p<0.001) and cancer-specific mortality (HR: 1.90; 95% CI, 1.52-2.37; p<0.001). The addition of ENE to a multivariable model that included pT stage, tumor grade, age, gender, lymphovascular invasion, surgical margin status, LN density, number of LNs removed, number of positive LNs, and adjuvant chemotherapy improved predictive accuracy for disease recurrence and cancer-specific mortality from 70.3% to 77.8% (p<0.001) and from 71.8% to 77.8% (p=0.007), respectively. The main limitation of the study is its retrospective nature.

CONCLUSIONS

ENE is an independent predictor of both cancer recurrence and cancer-specific mortality in RC patients with LNM. Knowledge of ENE status could help with patient counseling, clinical decision making regarding inclusion in clinical trials of adjuvant therapy, and tailored follow-up scheduling after RC.

[Lymphadenectomy for bladder cancer: current status and controversies]

Pelvic lymph node dissection is an integral part of the radical cystectomy procedure for patients with muscle-invasive bladder cancer. The optimal extent of the lymphadenectomy (LND) and mainly the proximal template boundary remain controversial issues. In view of the existing mapping studies and retrospective analyses, extended LND up to the mid-upper third of the common iliac vessels appears to provide further prognostic and therapeutic benefit and therefore should be defined as standard LND. This applies for all procedures irrespective of the choice of surgical approach (open surgery, minimally invasive approach). In this context total lymph node count is not a quality criterion because nodal yield is overly influenced by the individual patient's anatomy, surgical technique, template applied and pathological work-up. Consecutively, considerable inter-institutional differences result, which render any comparison impossible. Lymph node density is thought to be a superior prognostic factor, but it is similarly influenced by the above-mentioned factors. Concerning molecular techniques to improve the sensitivity of postoperative nodal staging further research is necessary. The two ongoing prospective randomized trials will potentially help to further define the optimal LND template.

Pelvic lymphadenectomy in the treatment of invasive bladder cancer: literature review

The standard surgical treatment of invasive bladder cancer is the radical cystectomy and pelvic lymph node dissection (PLND). Up to one-third of patients with invasive bladder cancer have lymph node metastasis. Thus, PLND has important therapeutic and prognostic benefits. The number of lymph nodes that should be removed and the extent of the PLND are still a controversial issue. Recently, the trend of PLND increased toward more extended PLND. Several prognostic factors related to PLND were reported in the literature. In this paper, we will discuss the different PLND templates, number of lymph nodes that should be resected, lymph node density, lymphovascular invasion, tumor burden, extracapsular extension, and the aggregate lymph node metastasis diameter.

Lymphadenectomy in management of invasive bladder cancer

Radical cystectomy with pelvic lymphadenectomy represents the gold standard for treatment of muscle-invasive bladder cancer. Extent of the lymph node dissection and lymph node involvement during radical cystectomy are the most powerful prognostic factors associated with poor oncological outcome. However, the optimal boundaries of the lymph node dissection during a radical cystectomy are controversial. The published literature based mostly on retrospective studies suggests that increasing the number of nodes excised may have therapeutic and diagnostic benefits without significantly increasing the surgical morbidity. These conclusions are, however, influenced by selection and surgeon biases, inconsistencies in the quality of the surgery, and node count variability. In this paper, we establish the current understanding about the utility of lymphadenectomy during a radical cystectomy for muscle-invasive bladder cancer.

Lymph node assessment and lymphadenectomy in bladder cancer

Lymph node status is a key prognostic indicator in patients with bladder cancer, so lymphadenectomy is important for accurate staging. Moreover, lymphadenectomy is curative for some patients with nodal metastases. Although there is evidence that the quality of regional node dissection is associated with oncologic outcome, controversy exists because other factors may also explain this observation. Consequently, there is no consensus regarding the optimal extent of lymphadenectomy and number of nodes that should be assessed.

Bladder cancer

PURPOSE OF REVIEW

This article reviews the diagnosis and management of bladder cancer with an emphasis on studies and developments over the past year.

RECENT FINDINGS

Cystoscopy remains the mainstay in the detection and surveillance of bladder cancer, though efforts continue in the development of urinary bladder cancer markers. Superficial bladder cancer continues to be managed predominantly through transurethral resection with perioperative instillation of chemotherapy recommended for most patients. Intravesical bacille Calmette-Guerin (including a maintenance regimen) should be used for those at high risk for progression. Muscle invasive disease continues to be managed by radical cystectomy. Research continues on the use of laparoscopy, the effect on patient's health-related quality of life, and the potential role for bladder preservation strategies. The role of neoadjuvant versus adjuvant chemotherapy around the time of cystectomy remains to be resolved. The mainstays of chemotherapy remain methotrexate, vinblastine, doxorubicin, and cisplatin, and gemcitabine and cisplatin, but work is ongoing to develop new regimens, especially in patients who cannot take cisplatin.

SUMMARY

Although great strides continue to be made each year in the diagnosis and management of bladder cancer considerably more work needs to be done in order to improve the lives of our patients with this disease.