Magnetic resonance imaging in the staging of bladder cancer

VI-RADS score system - A primer for urologists

Bladder cancer (BCa) is one of the most common cancers worldwide and is also considered to be one of the most relapsing and aggressive neoplasms. About 30% of patients will present with muscle invasive disease, which is associated with a higher risk for metastatic disease. The aim of this article is to review the state of art imaging in Radiology, while providing a complete guide to urologists, with case examples, for the rationale of the development of the Vesical Imaging Reporting and Data System (VI-RADS), a scoring system emphasizing a standardized approach to multiparametric Magnetic Resonance Imaging (mpMRI) acquisition, interpretation, and reporting for BCa. Also, we examine relevant external validation studies and the consolidated literature of mpMRI for bladder cancer. In addition, this article discusses some of the potential clinical implications of this scoring system for disease management and follow-up.

Comparative sensitivity and specificity of imaging modalities in staging bladder cancer prior to radical cystectomy: a systematic review and meta-analysis

PURPOSE

The detection of lymph node metastases in bladder cancer has a significant impact on treatment decisions. Multiple imaging modalities are available to clinicians including magnetic resonance imaging, computed tomography and positron emission tomography. We aimed to investigate the utility of alternate imaging modalities on pre-cystectomy imaging in bladder cancer for the detection of lymph node metastases.

METHODS

We performed systematic search of Web of Science (including MEDLINE), EMBASE and Cochrane libraries in accordance with the PRISMA statement. Studies comparing lymph node imaging findings with final histopathology were included in our analysis. Sensitivity and specificity data were quantified using patient-based analysis. A true positive was defined as a node-positive patient on imaging and node positive on histopathology. Meta-analysis of studies was performed using a mixed-effects, hierarchical logistic regression model.

RESULTS

Our systematic search identified 35 articles suitable for inclusion. MRI and PET have a higher sensitivity than CT while the specificity of all modalities was similar. The summary MRI sensitivity = 0.60 (95% CI 0.44-0.74) and specificity = 0.91 (95% CI 0.82-0.96). Summary PET/CT sensitivity = 0.56 (95% CI 0.49-0.63) and specificity = 0.92 (95% CI 0.86-0.95). Summary CT sensitivity = 0.40 (95% CI 0.33-0.49) and specificity = 0.92 (95% CI 0.86-0.95).

CONCLUSION

MRI and PET/CT provides superior sensitivity compared to CT for detection of positive lymph nodes in bladder cancer prior to cystectomy. There is variability in the accuracy that current imaging modalities achieve across different studies. A number of other factors impact on detection accuracy and these must be considered.

Matrix metalloproteinase-7 as a marker of metastasis and predictor of poor survival in bladder cancer

Matrix metalloproteinases (MMPs) play an important role in tumor progression and metastasis. Here, we investigated the prognostic relevance of MMP-7 in urinary bladder cancer. MMP-7 gene expression was measured in tissue samples of 101 patients using quantitative real-time PCR. Circulating MMP-7 serum levels of 98 individuals (79 patients and 19 controls) were analyzed by enzyme-linked immunosorbent assay. The results were compared with the clinical follow-up data, performing Kaplan-Meier log-rank test as well as univariate and multivariate Cox analysis. In representative cases, immunohistochemical analysis for MMP-7 was performed. We detected significantly elevated MMP-7 levels both in tissue and serum samples of patients with metastatic disease (P = 0.001 and P = 0.002). Multivariate analysis revealed that high MMP-7 tissue expression and serum concentration are stage- and grade-independent predictors of both metastasis-free (hazard ratio [HR] = 3.80, 95% confidence interval [CI], 1.29-11.23, P = 0.016, and HR = 2.53, 95% CI, 1.01-6.37, P = 0.048) and disease-specific survival (HR = 1.89, 95% CI, 1.00-3.55, P = 0.050 and HR = 1.95, 95% CI, 1.03-3.71, P = 0.041). Based on these findings, we conclude that MMP-7 is a promising marker to detect present and to predict future metastasis. Serum MMP-7 analysis provides information about the risk of metastasis before surgery which could help to optimize therapeutic procedures. Furthermore, high MMP-7 tissue and/or serum levels could identify patients most likely to benefit from early adjuvant chemotherapy.

Bladder cancer: modeling and translation

Transitional cell carcinoma of the bladder is a common malignancy worldwide that is associated with significant morbidity and mortality. Although superficial tumors can often be treated effectively, invasive cancers not only require invasive surgery, but are also refractory to aggressive chemotherapy and radiotherapy. In this issue of Genes & Development, Puzio-Kuter and colleagues (pp. 675-680) describe an elegant genetically engineered murine model of bladder cancer that recapitulates many of the cardinal features of the human disease. The development of such models together with the application of new approaches to enumerate the complement of genetic alterations in bladder will provide new insights into the molecular nature of this disease. Moreover, the anatomy of this urinary malignancy provides a unique opportunity for innovative translational studies.

Outcome after radical cystectomy with limited or extended pelvic lymph node dissection

PURPOSE

We compared recurrence patterns and survival of patients with urothelial bladder cancer undergoing radical cystectomy who either had limited or extended pelvic lymph node dissection at 2 institutions between 1987 and 2000.

MATERIALS AND METHODS

Two consecutive series of patients treated with radical cystectomy and limited pelvic lymph node dissection (336; Cleveland Clinic) and extended pelvic lymph node dissection (322; University of Bern) were analyzed. All cases were staged N0M0 prior to radical cystectomy, and none were treated with neoadjuvant radiotherapy or chemotherapy. Patients with PTis/pT1 and pT4 disease were excluded from analysis. Pathological characteristics based on the 1997 TNM system and recurrence patterns were determined.

RESULTS

The overall lymph node positive rate was 13% for patients with limited and 26% for those who had extended pelvic lymph node dissection. The 5-year recurrence-free survival of patients with lymph node positive disease was 7% for limited and 35% for extended pelvic lymph node dissection. The 5-year recurrence-free survival for pT2pN0 cases was 67% for limited and 77% for extended pelvic lymph node dissection, and the respective percentages for pT3pN0 cases were 23% and 57% (p <0.0001). The 5-year recurrence-free survival for pT2pN0-2 cases was 63% for limited and 71% for extended pelvic lymph node dissection, and for pT3pN0-2 cases the respective figures were 19% and 49% (p <0.0001). Incidence of local and systemic failure correlated closely with pathological stage for both series.

CONCLUSIONS

Our data suggest that limited pelvic lymph node dissection is associated with suboptimal staging, poorer outcome for patients with node positive and node negative disease, and a higher rate of local progression. Extended pelvic lymph node dissection allows for more accurate staging and improved survival of patients with nonorgan confined and lymph node positive disease.

Outcomes in patients with urothelial carcinoma of the bladder with limited pelvic lymph node dissection

OBJECTIVES

To evaluate the rates of local and systemic progression (LP and SP), recurrence-free survival and overall survival for patients with urothelial carcinoma of the bladder with limited pelvic lymph node dissection (PLND) in 1987-2000.

PATIENTS AND METHODS

A consecutive series was analysed of 385 patients (median age 61.9 years, range 30.7-83.8) treated by limited bilateral PLND and radical cystectomy (RC) between 1987 and 2000, with negative surgical margins on final pathology. All patients were staged N0M0 before RC, and none received neoadjuvant radiotherapy or chemotherapy. The boundaries of the limited PLND were the pelvic side-wall between the genitofemoral and obturator nerves, and bifurcation of iliac vessels to the circumflex iliac vein. LP was defined as a radiographic soft-tissue density of > or = 2 cm below the bifurcation of the aorta. Pathological characteristics, based on the 1997 Tumour-Nodes-Metastasis system, recurrence patterns, and recurrence-free and overall survival, were determined. RESULTS The median (range) overall follow-up was 45.1 (1.1-165.6) months; the number of lymph nodes (LNs) reported per patient was 12 (2-32). Of the 385 patients, 130 (33.8%) had evidence of LP and 60 (15.6%) of SP. The 5-year recurrence-free and overall survival rates were both 71% for patients with organ-confined, N0 tumours, and 23% and 26% for unconfined, N0 tumours. Positive LNs were found in 45 (12%) patients, who had a recurrence-free and overall survival rate of 9% at 5 years.

CONCLUSION

Compared with published reports of similar cohorts of patients managed with RC and extended PLND, the present study suggests that limited PLND is associated with suboptimal staging, greater rates of LP, and lower rates of recurrence-free survival, particularly for patients with unconfined or LN-positive disease.

Prediction of Extravesical Disease by Preoperative Serum Markers in Patients With Clinically Organ Confined Invasive Bladder Cancer

PURPOSE

We assessed the value of preoperative levels of CEA, CA-125 or CA 19-9 in patients with clinically organ confined bladder cancer to predict pathological extravesical and/or node positive disease.

MATERIALS AND METHODS

Serum levels of CEA, CA-125 and CA 19-9 were measured prospectively in all patients scheduled for cystectomy for clinically organ confined bladder cancer between September 1999 and May 2004. Biomarker expression was compared between patients with pathologically organ confined disease (pT2 or less, pN0) and patients with extravesical disease (greater than pT2, or pN1 or greater), and between patients with pathologically node negative (any pT, pN0) and node positive disease (any pT, pN1 or greater).

RESULTS

Of the 91 patients enrolled, 46 had (51%) pathologically organ confined tumors, 45 (49%) had extravesical disease and 17 (19%) had positive lymph nodes. Preoperative serum levels of all markers were significantly higher in cases of extravesical disease than in organ confined disease. On multivariate analysis CEA with an odds ratio of 8.6 (95% CI 1.51-48.6) and CA-125 with an OR of 29.5 (95% CI 3.6-242.6) proved independent predictors of extravesical disease. CA-125 and CA 19-9 levels were significantly higher in patients with node positive disease than in those with node negative disease. On multivariate analysis CA-125 with an OR of 22.2 (95% CI 3.8-129) and CA 19-9 with an OR of 5.2 (95% CI 1.09-24.76) proved independent predictors of node positive disease.

CONCLUSIONS

Increase in serum tumor markers before cystectomy in patients with clinically organ confined muscle invasive bladder cancer is a strong indicator of the presence of extravesical and node positive disease.

Current status of establishing standards for lymphadenectomy in the treatment of bladder cancer

PURPOSE

Pelvic lymph node dissection at the time of radical cystectomy is a crucial component of the surgical management of invasive bladder cancer. No established therapeutic or diagnostic guidelines regarding pelvic lymph node dissection are, however, currently available. We reviewed the past and contemporary literature to clarify the current role of pelvic lymph node dissection both as a staging modality as well as potential therapeutic intervention.

RECENT FINDINGS

The role of pelvic lymph node dissection has evolved over the past 60 years. Although the added benefits of radical cystectomy over simple cystectomy alone are accepted, an optimal template for pelvic lymph node dissection has not been established. Increasing evidence suggesting therapeutic and diagnostic benefits by extending the boundaries of lymphadenectomy or by increasing the number of nodes excised has been reported. Much of the recent literature, however, is based on retrospective studies, and is influenced by factors such as node count variability, inconsistencies in the quality of the surgery, and the biases in patient selection. Currently, the optimal boundaries of pelvic lymph node dissection and the minimum number of nodes to be pathologically examined remain undetermined.

SUMMARY

The diagnostic and therapeutic benefits obtained by extending the limits of lymphadenectomy are compelling but inconclusive. Establishing standards for pelvic lymph node dissection will not only increase the consistency of staging and improve the design and interpretation of clinical trials in invasive bladder cancer but also help to identify and optimize the therapeutic benefits of lymphadenectomy. Prospective, randomized trials will be needed to properly establish the extent of lymphadenectomy required to obtain such benefits.

FDG-PET for preoperative staging of bladder cancer

PURPOSE

The presence of lymph node involvement (N) and distant metastasis (M) in patients with invasive bladder carcinoma is a major determinant of survival and, therefore, a pivotal element in the therapeutic management. The aim of this prospective study was to evaluate the use of( 18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in this indication.

METHODS

Whole-body FDG-PET and computed tomography (CT) were performed in 55 patients with non-metastatic invasive bladder cancer for preoperative staging. Correlative imaging of PET with CT was performed, leading to a PET(CT) result. The imaging results were compared with the gold standard, consisting of histopathology (lymphadenectomy, guided biopsy) or clinical follow-up for 12 months, and related to overall survival using the Kaplan-Meier method.

RESULTS

The gold standard was available in 40 patients and indicated NM-positive disease in 15 patients (12 N lesions, 8 M lesions), and NM-negative disease in 25 patients. For the diagnosis of NM-positive disease, the sensitivity, specificity and accuracy of PET(CT) were 60%, 88% and 78%, respectively. Diagnostic discordances between PET(CT) and CT alone were found in 9/40 patients, among whom PET was correct in six (15%): three with true-positive and one with true-negative distant metastases, and two with true-negative lymph nodes. Median survival time of patients in whom PET(CT) indicated NM-positive disease was 13.5 months, compared with 32.0 months in the patients with a NM-negative PET(CT) (p=0.003).

CONCLUSION

Addition of metabolism-based information provided by FDG-PET to CT in the preoperative staging of invasive bladder carcinoma yields a high diagnostic and prognostic accuracy.

Critique of laparoscopic lymphadenectomy in genitourinary oncology

Regional lymphadenectomy is prognostic and selectively therapeutic in urologic oncology. The role of lymphadenectomy continues to be defined with the evolving multimodal management of genitourinary malignancies. Laparoscopy is playing a greater role in the management of genitourinary malignancies and thus, it is germane to critique the role of laparoscopic lymphadenectomy in the management of these tumors. Review of the literature suggests that laparoscopic pelvic lymphadenectomy is feasible with nodal yields commensurate to those in open published series. Although laparoscopic retroperitoneal lymph node dissection for nonseminomatous germ cell tumor is feasible, the technique and efficacy of this procedure require further investigation.

The evolving role of pelvic lymphadenectomy in the treatment of bladder cancer

Regional lymphadenectomy is integral to the surgical management of high-grade invasive bladder cancer. A growing body of evidence suggests that a lymph node dissection may provide not only improved prognostic information, but also a clinically significant therapeutic benefit for both lymph node positive and negative patients undergoing radical cystectomy. While the inclusion of lymph node resection in conjunction with radical cystectomy for patients with clinically negative nodes is well accepted, the extent of the nodal dissection remains highly contentious. Similarly, the benefit of node dissection for patients with advanced disease and gross adenopathy or for those with superficial disease (Ta, T1 or TIS) remains a topic of heated debate. This review describes the historical evolution of lymphadenectomy in the surgical treatment of bladder cancer and provides a comprehensive review of the current literature addressing the role of lymph node dissection in the treatment of bladder cancer.

Preoperative Plasma Soluble E-Cadherin Predicts Metastases to Lymph Nodes and Prognosis in Patients Undergoing Radical Cystectomy

PURPOSE

We have previously reported that high urinary levels of soluble E-cadherin (sE-cadherin) are associated with an increased risk of bladder cancer. We determined whether plasma levels of sE-cadherin are associated with bladder cancer stage and prognosis.

MATERIALS AND METHODS

The study group consisted of 50 patients who underwent radical cystectomy for muscle invasive cancer or intravesical therapy refractory Tis, Ta, or T1 bladder cancer; and 40 men without cancer. Preoperative plasma levels of sE-cadherin were measured using a commercially available enzyme-linked immunosorbent assay kit.

RESULTS

Plasma sE-cadherin was higher in patients with bladder cancer than in healthy subjects (p <0.0001) and it was elevated in patients with metastases to regional and distant lymph nodes (p = 0.019 and 0.024, respectively). When adjusted for the effects of clinical stage and grade, preoperative sE-cadherin was independently associated with metastases to regional lymph nodes (p = 0.028) and disease progression (p = 0.006) but not with bladder cancer mortality. In postoperative models preoperative sE-cadherin and lymph node metastases were associated with disease progression (p = 0.017 and 0.042, respectively) after adjusting for the effects of pathological stage, grade and lymphovascular invasion but only lymph node metastases were associated with cancer specific mortality (p = 0.007).

CONCLUSIONS

Higher plasma sE-cadherin is associated with bladder cancer. Higher preoperative plasma sE-cadherin has the potential to identify patients with metastases to regional and distant lymph nodes who are at increased risk for failure of local therapy with curative intent. These patients may benefit from more extensive lymph node dissection and/or combined modality treatment regimens.

The role of pelvic lymph node dissection as a predictive and prognostic factor in bladder cancer

The aim of this study was to evaluate the value of pelvic lymph node dissection (PLND) performed as a separate procedure in a consecutive Danish bladder cancer cohort and also to analyse if the number of lymph nodes excised had an impact on outcome. From 1992 to 1998, 339 cystectomy candidates were retrospectively reviewed. Based on a preoperative PLND, 248 patients (10% N+) underwent radical cystectomy and 91 (87% N+) underwent radio- or chemotherapy. The median follow-up was 6.3 years. PLND was able to separate N+ from N0 patients with a false-negative rate of 3% compared with the following cystectomy. Lymph node-positive patients treated with cystectomy (n=24) all died from their bladder cancer. Therefore, accurate pathological N classification before the treatment decision seems worthwhile. The median number of lymph nodes excised was six and the number of lymph nodes had an independent prognostic impact on survival. This underlines the need for guidelines for surgical lymphadenectomy and the pathological assessment of lymph nodes in bladder cancer.

Preoperative plasma levels of transforming growth factor beta(1) strongly predict clinical outcome in patients with bladder carcinoma

BACKGROUND

Elevated local and circulating levels of transforming growth factor (TGF)-beta(1) have been associated with cancer invasion, progression, and metastasis. The authors tested the hypothesis that preoperative plasma TGF-beta(1) levels would independently predict cancer stage and prognosis in patients with transitional cell carcinoma (TCC) of the urinary bladder.

METHODS

The study group consisted of 51 patients who underwent radical cystectomy for muscle-invasive or intravesical immuno- and/or chemotherapy refractory Tis, Ta, or T1 TCC (median follow-up, 45.7 months). Preoperative plasma levels of TGF-beta(1) were measured and correlated with pathologic features and clinical outcome. Transforming growth factor-beta(1) levels also were measured in 44 healthy men without any cancer.

RESULTS

The mean preoperative plasma TGF-beta(1) level in patients who eventually developed metastases to distant (11.9 +/- 0.9 ng/mL) or regional (9.6 +/- 2.4 ng/mL) lymph nodes was significantly higher than that in patients with nonmetastatic muscle-invasive TCC (5.4 +/- 1.1 ng/mL), which, in turn, was significantly higher than that in patients with nonmetastatic Tis, Ta, or T1 TCC (4.5 +/- 1.2 ng/mL) and healthy subjects (4.5 +/- 1.2 ng/mL; P < 0.001). Preoperative plasma TGF-beta(1) level was an independent predictor of lymphovascular invasion (P = 0.002), metastases to lymph nodes (P = 0.030), disease recurrence (P = 0.009), and disease specific survival (P = 0.015). In a subgroup of patients with muscle-invasive TCC, TGF-beta(1) level was associated with disease recurrence (P = 0.005) and death from bladder carcinoma (P = 0.001).

CONCLUSIONS

The authors confirm that plasma TGF-beta(1) levels are elevated in patients with muscle-invasive TCC before cystectomy. Transforming growth factor-beta(1) levels are highest in patients with bladder carcinoma metastatic to lymph nodes and are a strong independent predictor of disease recurrence and disease specific mortality.

Diagnosis and treatment of pelvic lymph node metastasis in bladder control

BACKGROUND AND METHODS

Bipedal lymphography and percutaneous fine needle aspiration biopsy (FNAB) of pelvic lymph node was done in 200 patients with bladder cancer.

RESULTS

A diagnosis of metastasis to the pelvic lymph node was obtained by this method in 34 patients. Of these 34 patients, only 12 (35%) were positive or suspected of having pelvic lymph node metastasis by computed tomography. Sixteen patients (47%) had unequivocally positive or highly suspicious lymphogram and 18 patients (53%) had normal lymphogram. Seventy-eight cases, including eight FNAB-positive cases, were treated by radical cystectomy and regional lymph node dissection. Sensitivity, specificity, positive predictive value and negative predictive value of FNAB were 57, 100, 100 and 91%, respectively. Thirteen FNAB-positive M0 patients could be treated by multimodality therapy and evaluated after neoadjuvant therapy by repeated lymphography and FNAB. All were changed to N0 by FNAB after neoadjuvant therapy. In eight patients treated by total cystectomy and lymph node dissection, four had down staged to pN0 but four had one positive node. In five follow-up cases without surgery, one had recurrent pelvic lymph node metastasis 35 months later. Cause-specific survival of these patients was 76% at 5 years and 57% at 8 years.

CONCLUSIONS

Pretreatment diagnosis of pelvic lymph node metastasis and multimodality therapy may improve the prognosis of regional lymph node-positive bladder cancer. Because it is difficult to diagnose pN1 using FNAB, radical operation should be performed even if neoadjuvant therapy is effective and down staging is obtained.