The importance of an extended lymphadenectomy in the management of high-grade invasive bladder cancer

Log Odds of Positive Lymph Nodes (LODDS) as an Independent Predictor of Overall Survival Following Radical Cystectomy in Urothelial Bladder Cancer: Time to Rethink Conventional Node Staging

BACKGROUND

Radical cystectomy (RC) with lymph node dissection is the mainstay of treatment for patients with muscle-invasive bladder cancer (MIBC) and high risk non-MIBC. The American Joint Committee on Cancer's (AJCC) node staging and lymph node ratio (LNR) systems are used in estimating prognosis; however, they do not directly factor in negative dissected nodes. In this study, we evaluated the log odds of positive lymph nodes (LODDS), a novel measure of nodal involvement, as a predictor of survival.

PATIENTS AND METHODS

Eighty-three patients who underwent RC were retrospectively included and their demographic and clinical data were collected. Kaplan-Meier curve and Cox regression were used for survival analyses.

RESULTS

Median number of dissected lymph nodes was 13 (range 3-45). ROC curve analysis indicated -0.92 as the optimal LODDS cutoff. LODDS > -0.92 was associated with higher T stage, lymphovascular invasion, and significantly worse overall survival (OS) (mean OS 18.6 vs. 45.1 months, P-value < .001). Furthermore, we evaluated AJCC node staging, LNR, and LODDS in three separate multivariable Cox regression models. Among 3 different measures of nodal disease burden, only LODDS was an independent predictor of OS (HR 2.71, 95% CI 1.28-5.73, P = .009).

CONCLUSIONS

Our results show that LODDS is an independent predictor of OS and outperforms AJCC node staging and LNR in forecasting prognosis among patients with urothelial bladder cancer who undergo RC.

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.

The anatomical limits and oncological benefit of lymphadenectomy in muscle invasive bladder cancer

BACKGROUND

Lymphadenectomy is part of standard treatment for muscle invasive bladder cancer. The objective of this review is to provide an up-to-date review on the available scientific evidence in this field.

ACQUISITION OF EVIDENCE

We conducted a literature review in PubMed of relevant articles up to the present (2016). We found a systematic review published in 2014 that included the comparative studies published up to that year, and we updated the review with new relevant publications since that date.

SYNTHESIS OF THE EVIDENCE

The number of lymph nodes is not the best indicator for determining the quality of the lymphadenectomy given that the number can vary depending on numerous factors that depend not only on the surgeon but also on the patient and on the pathologist. The definition of standard anatomical territories and a meticulous extraction of the lymph nodes in these territories are more reproducible than the numbers of nodes removed. The optimal extension of lymphadenectomy is a topic of debate. The evidence published to date indicates that any extension of lymphadenectomy is better than not performing it, although it appears that limited lymphadenectomy is insufficient for the oncological control of the disease and that superextended lymphadenectomy provides no oncological benefit versus extended lymphadenectomy.

CONCLUSIONS

Despite a certain amount of controversy in terms of the optimal extension of lymphadenectomy, performing lymphadenectomy in all cases appears to be recommendable according to the available evidence. Extended lymphadenectomy provides greater oncological benefit than more limited dissections, while more extensive lymphadenectomies are not recommended.

Lymph node density as a prognostic variable in node-positive bladder cancer: a meta-analysis

Background

Although lymph node (LN) status and the LN burden determine the outcome of bladder cancer patients treated with cystectomy, compelling arguments have been made for the incorporation of LN density into the current staging system. Here, we investigate the relationship between LN density and clinical outcome in patients with LN-positive disease, following radical cystectomy for bladder cancer.

Methods

PubMed, SCOPUS, the Institute for Scientific Information Web of Science, and the Cochrane Library were searched to identify relevant published literature.

Results

Fourteen studies were included in the meta-analysis, with a total number of 3311 patients. Of these 14 publications, 6 studies, (533 patients), 10 studies (2966 patients), and 5 studies (1108 patients) investigated the prognostic association of LN density with disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS), respectively. The pooled hazard ratio (HR) for DFS was 1.45 (95 % confidence interval [CI], 1.10–1.91) without heterogeneity (I² = 0 %, p = 0.52). Higher LN density was significantly associated with poor DSS (pooled HR, 1.53; 95 % CI, 1.23–1.89). However, significant heterogeneity was found between studies (I² = 66 %, p = 0.002). The pooled HR for OS was statistically significant (pooled HR, 1.45; 95 % CI, 1.11–1.90) without heterogeneity (I² = 42 %, p = 0.14). The results of the Begg and Egger tests suggested that publication bias was not evident in this meta-analysis.

Conclusions

The data from this meta-analysis indicate that LN density is an independent predictor of clinical outcome in LN-positive patients. LN density may be useful in future staging systems, thus allowing better prognostic classification of LN-positive bladder cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1448-x) contains supplementary material, which is available to authorized users.

Improving bladder cancer treatment with radiotherapy using separate intensity modulated radiotherapy plans for boost and elective fields

The aim of this study is to investigate to what extent IMRT can decrease the dose to the organs at risk in bladder cancer treatment compared with conformal treatment while making separate treatment plans for the elective field and the boost. Special attention is paid to sparing small intestines. Twenty patients who were treated with the field-in-field technique (FiF) were re-planned with intensity modulated radiotherapy (IMRT) using five and seven beams, respectively. Separate treatment plans were made for the elective field (including the pelvic lymph nodes) and the boost, which enables position correction for bone and tumour separately. The prescribed dose was 40 Gy to the elective field and 55 or 60 Gy to the planning target volume (PTV). For bladder and rectum, V(45Gy) and V(55Gy) were compared, and for small intestines, V(25Gy) and V(40Gy.) The dose distribution with IMRT conformed better to the shape of the target. There was no significant difference between the techniques in dose to the healthy bladder. The median V(40Gy) of the small intestines decreased from 114 to 66 cc (P = 0.001) with five beam IMRT, and to 55 cc (P = 0.001) with seven beam IMRT compared with FiF. V(45Gy) for rectum decreased from 34.2% to 17.5% (P = 0.004) for both five and seven beam plans, while V(55Gy) for rectum remained the same. With IMRT, a statistically significant dose decrease to the small intestines can be achieved while covering both tumour and elective PTV adequately.

Risk factors for recurrence following radical cystectomy for pathologic node negative bladder cancer

BACKGROUND AND OBJECTIVES

To evaluate for risk factors associated with bladder cancer recurrence in patients with pathologically negative lymph nodes.

METHODS

A retrospective review of 405 patients undergoing radical cystectomy for bladder cancer between 1996 and 2008 was performed. Patients with node-positive disease and <6 months of follow up were excluded. Clinical and pathological characteristics including stage, lymphadenectomy type (standard vs. extended), number of nodes removed, margin status, lymphovascular invasion (LVI), perineural invasion (PNI), presence of carcinoma in situ, and site of recurrence were evaluated. Kaplan-Meier analysis was used to calculate 5-year recurrence-free survival stratified by lymph node yield.

RESULTS

Two hundred sixty patients met the inclusion criteria. Overall, 80 (30.8%) patients recurred within 5 years. Univariate analysis identified LVI, PNI, extravesical disease, positive margins, and lymph node yield <14 to be significant predictors of disease recurrence. On multivariate analysis LVI, PNI, and node yield <14 retained significance (P = 0.01, 0.037, 0.038, respectively). There was no difference in 5-year recurrence free survival when stratified by node yield using the Kaplan-Meier method (P = 0.138).

CONCLUSIONS

We identified LVI, PNI, and lymph node yield <14 as three independent risk factors for bladder cancer recurrence in patients with node-negative bladder cancer.

Predicting survival after radical cystectomy for bladder cancer

Accurate prediction is essential for patient counselling, appropriate selection of treatments and determination of eligibility for clinical trials. In this review we assess the available determinants of oncological outcome after radical cystectomy (RC) for transitional cell carcinoma of the urinary bladder. We reviewed previous publications to provide guidelines in terms of criteria, limitations and clinical value of available tools for predicting patient outcome after RC. Our findings suggest that while individual surgical, patient and pathological features provide useful estimates of survival outcome, the inherent heterogeneity of tumour biology and patient characteristics leads to significant variation in outcome. By incorporating all relevant continuous predictive factors for individual patients, integrative predictive models, such as nomograms or artificial neural networks, provide more accurate predictions and generally surpass clinical experts at predicting outcomes. Nonetheless, there is a clear need for the development and validation of molecular biomarkers and their incorporation into multivariable predictive tools. Significant progress has been made in identifying important molecular markers of disease and the development of multifactorial tools for predicting the outcome after RC.

[The usefulness of pelvic lymphadenectomy in bladder cancer]

OBJECTIVE

[corrected] To assess the usefulness of pelvic lymphadenectomy in bladder cancer.

METHODS AND RESULTS

With the followings key words: "bladder cancer, lymphadenectomy, lymph node metastasis" we search in Medline/PubMed database for papers published during the last ten years. Thirty three papers fulfilling the search criteria were selected.

CONCLUSIONS

It does not exist any randomized prospective study comparing different pelvic lymphadenectomy techniques. Nodal metastasis in bladder cancer after radical cystectomy and pelvic lymphadenectomy ranged between 18% and 28%. Standard lymphadenectomy could improve tumor staging and probably survival in selected patients. It is advisable to remove, as a quality parameter, at least 10 to 14 nodes in a pelvic lymphadenectomy. Lymph node density seems to predict survival better than TNM staging system. It is advisable to perform separate lymph node dissection rather than en-bloc.

Multispectral imaging autofluorescence microscopy in colonic and gastric cancer metastatic lymph nodes

BACKGROUND & AIMS

The lymphadenectomy and extended lymphadenectomy procedures have been points of controversy in surgical oncology. The methods available for the detection of metastatic lymph nodes are numerous. These include lymphoscintigraphy and radiolabeled antibody detection, but in most cancers the currently used technique is sentinel lymph node identification, performed primarily through the use of immunohistochemistry. We propose the application of autofluorescence (AF)-based techniques for lymph node evaluation in colorectal and gastric tumors.

METHODS

We studied 30 clinical cases: 15 colorectal cancers and 15 gastric cancers. All of the patients were in the advanced stages of the disease and were candidates for adjuvant therapy. Autofluorescence microspectroscopy and multispectral imaging autofluorescence microscopy have been used to analyze the AF emission of metastatic lymph node sections, excited with 365-nm wavelength radiation. The AF spectra were recorded in the range of 400-700 nm. Monochrome AF images were acquired sequentially through interference filters peaked at 450, 550, and 650 nm, and then combined together in a single red-green-blue image. The AF pattern and the emission spectrum of metastatic lymph nodes have unique characteristics that can be used to distinguish them from the normal ones.

RESULTS

The results, compared with standard histopathologic procedures and with specific staining methods, supplied a satisfactory validation of the proposed technique, revealing the possibility of improving the actual diagnostic procedures for malignant lymph node alterations.

CONCLUSIONS

With the development of appropriate instrumentation, the proposed technique could be particularly suitable in intrasurgical diagnosis of metastatic lymph nodes.

[Lymphadenectomy for bladder cancer. Diagnostic and prognostic significance as well as therapeutic benefit]

BACKGROUND

Pelvic lymphadenectomy for invasive bladder cancer is not a standardized procedure and its relevance for staging and prognoses is still under discussion. A number of retrospective studies have demonstrated a positive correlation between extent of lymphadenectomy and prognosis after radical cystectomy.

MATERIALS AND METHODS

In a retrospective study, we correlated the extent of lymphadenectomy with survival after radical cystectomy. Thereafter, we conducted a prospective study to investigate the limits of pelvic lymphadenectomy and the pattern of lymphatic spread.

RESULTS

Retrospectively, we found a significantly better survival for patients when 15 and more lymph nodes were removed. The individual surgeon was also evaluated as an important prognostic factor.

CONCLUSIONS

Based on retrospective data, an extended and complete pelvic lymphadenectomy improves the prognosis. The cranial border should be at least at the level of the aortic bifurcation. A prospective randomized study will have to clarify the effect of lymphadenectomy on the prognosis of patients after radical cystectomy.