Risk prediction models of locoregional failure after radical cystectomy for urothelial carcinoma: external validation in a cohort of korean patients

Study Protocol of the Bladder Adjuvant RadioTherapy (BART) Trial: A Randomised Phase III Trial of Adjuvant Radiotherapy Following Cystectomy in Bladder Cancer

AIMS

To assess the efficacy and safety of adjuvant radiotherapy in patients with high-risk muscle-invasive bladder cancer (MIBC) following radical cystectomy (RC) and chemotherapy.

MATERIALS AND METHODS

The BART (Bladder Adjuvant RadioTherapy) trial is an ongoing multicentric, randomised, phase III trial comparing the efficacy and safety of adjuvant radiotherapy versus observation in patients with high-risk MIBC. The key eligibility criteria include ≥pT3, node-positive (pN+), positive margins and/or nodal yield <10, or, neoadjuvant chemotherapy for cT3/T4/N+ disease. In total, 153 patients will be accrued and randomised, in a 1:1 ratio, to either observation (standard arm) or adjuvant radiotherapy (test arm) following surgery and chemotherapy. Stratification parameters include nodal status (N+ versus N0) and chemotherapy (neoadjuvant chemotherapy versus adjuvant chemotherapy versus no chemotherapy). For patients in the test arm, adjuvant radiotherapy to cystectomy bed and pelvic nodes is planned with intensity-modulated radiotherapy to a dose of 50.4 Gy in 28 fractions using daily image guidance. All patients will follow-up with 3-monthly clinical review and urine cytology for 2 years and subsequently 6 monthly until 5 years, with contrast-enhanced computed tomography abdomen pelvis 6 monthly for 2 years and annually until 5 years. Physician-scored toxicity using Common Terminology Criteria for Adverse Events version 5.0 and patient-reported quality of life using the Functional Assessment of Cancer Therapy - Colorectal questionnaire is recorded pre-treatment and at follow-up.

ENDPOINTS AND STATISTICS

The primary endpoint is 2-year locoregional recurrence-free survival. The sample size calculation was based on the estimated improvement in 2-year locoregional recurrence-free survival from 70% in the standard arm to 85% in the test arm (hazard ratio 0.45) using 80% statistical power and a two-sided alpha error of 0.05. Secondary endpoints include disease-free survival, overall survival, acute and late toxicity, patterns of failure and quality of life.

CONCLUSION

The BART trial aims to evaluate whether contemporary radiotherapy after standard-of-care surgery and chemotherapy reduces pelvic recurrences safely and also potentially affects survival in high-risk MIBC.

Perioperative therapy in muscle invasive bladder cancer

Radical cystectomy with bilateral pelvic lymph node dissection is the standard of care for muscle invasive bladder cancer (MIBC). The role of neoadjuvant and adjuvant therapy has evolved over the last 3–4 decades, and neoadjuvant chemotherapy (NACT) has now become the standard recommended treatment. However, there are many nuances to this and the utilization of chemotherapy has not been universal. The optimum chemotherapy regimen is still debated. Adjuvant radiation has a role in high-risk patients although not established and immunotherapy has shown promising results. We reviewed the evidence on NACT and adjuvant chemotherapy (ACT) regimens, NACT versus ACT, and the role of adjuvant radiotherapy and immunotherapy in MIBC.

Patterns of Locoregional Recurrence after Radical Cystectomy for Stage T3-4 Bladder Cancer: A Radiation Oncologist's Point of View

PURPOSE

Adjuvant radiotherapy (RT) has been performed to reduce locoregional failure (LRF) following radical cystectomy for locally advanced bladder cancer; however, its efficacy has not been well established. We analyzed the locoregional recurrence patterns of post-radical cystectomy to identify patients who could benefit from adjuvant RT and determine the optimal target volume.

MATERIALS AND METHODS

We retrospectively reviewed 160 patients with stage ≥ pT3 bladder cancer who were treated with radical cystectomy between January 2006 and December 2015. The impact of pathologic findings, including the stage, lympho-vascular invasion, perineural invasion, margin status, nodal involvement, and the number of nodes removed on failure patterns, was assessed.

RESULTS

Median follow-up period was 27.7 months. LRF was observed in 55 patients (34.3%), 12 of whom presented with synchronous local and regional failures as the first failure. The most common failure pattern was distant metastasis (40%). Among LRFs, the most common recurrence site was the cystectomy bed (15.6%). Patients with positive resection margins had a significantly higher recurrence rate compared to those without (28% vs. 10%, p=0.004). The pelvic nodal recurrence rate was < 5% in pN0 patients; the rate of recurrence in the external and common iliac nodes was 12.5% in pN+ patients. The rate of recurrence in the common iliac nodes was significantly higher in pN2-3 patients than in pN0-1 patients (15.2% vs. 4.4%, p=0.04).

CONCLUSION

Pelvic RT could be beneficial especially for those with positive resection margins or nodal involvement after radical cystectomy. Radiation fields should be optimized based on the patient-specific risk factors.

Adjuvant and Neoadjuvant Radiation Therapy for Locally Advanced Bladder Cancer

Local-regional failure for patients with ≥pT3 urothelial carcinoma after radical cystectomy is a significant clinical challenge. Prospective randomised trials have failed to show that chemotherapy reduces the risk of local-regional recurrences. Salvage treatment for local failures is difficult and often unsuccessful. There is promising evidence, particularly from a recent Egyptian National Cancer Institute trial, that radiation therapy plus chemotherapy can significantly reduce local recurrences compared with chemotherapy alone, and that this improvement in local-regional control may translate to meaningful improvements in disease-free and overall survival with acceptable toxicity. In light of the high rates of local failure following cystectomy for locally advanced disease and the progress that has been made in identifying patients at high risk of failure and the patterns of failure in the pelvis, the National Comprehensive Cancer Network guidelines were revised to include postoperative radiotherapy as an option to consider for patients with ≥pT3 disease. Here we review the problem of local-regional failure after cystectomy, identify patients who would probably benefit from adjuvant radiotherapy, review the patterns of pelvic failure after cystectomy, discuss technical details of radiation treatment and review the modern literature on this topic. Adjuvant radiotherapy should be considered as a treatment option for patients with locally advanced disease, especially those with positive margins or squamous cell carcinoma.

Oncologic Equipoise Between Robotic and Open Radical Cystectomy

Purpose: Our objective was to establish the incidence of positive surgical margins, recurrence patterns, and recurrence-free (RFS) and overall survival (OS) in a large cohort of patients undergoing robotic (robot-assisted radical cystectomy [RARC]) and open radical cystectomy (ORC). Materials and Methods: We performed a large retrospective cohort study at a high-volume academic tertiary referral center. Patients were those who underwent RC for bladder cancer from 2005 to 2017. Patients were allocated to ORC or RARC by patient and surgeon choice. Propensity matching and a multivariable analysis were performed to determine factors predictive of RFS and OS after RC. All analyses were done with SAS 9.4. Results: The study included 1885 patients, 13.5% of whom underwent RARC. There was no difference in positive soft tissue surgical margins (2.4% in ORC and 1.2% in RARC). There were no differences in recurrence patterns, nor in the severity of pathology distribution between the two cohorts. Peritoneal carcinomatosis was seen in 1.1% of ORC and 0.8% in RARC. Shorter RFS was associated with younger age (hazard ratio [HR] 1.04, 95% confidence interval [CI] 1.03-1.05, p < 0.001), neoadjuvant chemotherapy (HR 1.41, 95% CI 1.14-1.75, p = 0.002), higher pathologic stage (stage ≥T₂ HR 2.45, 95% CI 1.91-3.16, p < 0.001), lymph node positivity at cystectomy (HR 1.92, 95% CI 1.50-2.47, p < 0.001), and positive surgical margins (HR 1.49, 95% CI 1.09-2.05, p = 0.01). RFS and OS did not differ by surgical approach (HR 1.04, 95% CI 0.83-1.30), p = 0.75 and (HR 0.89, 95% CI 0.67-1.19), p = 0.43, respectively. Conclusion: The data from this study support continued use of RARC as a safe oncologic procedure, with similar outcomes to ORC.

[Adjuvant radiotherapy after radical cystectomy for muscle-invasive bladder cancer]

OBJECTIVES

Locoregional relapse (LRR) after cystectomy is a common early event associated with poor prognosis. The role of radiotherapy as an adjunct to radical cystectomy is not well-defined. The aim of this critical literature review is to provide an overview of the elements in favor of adjuvant radiation for patients treated for muscle-invasive bladder cancer.

MATERIAL AND METHODS

An exhaustive review of the literature was carried out using the Pubmed search tool with the following keywords: "radiotherapy" [Mesh], "adjuvant" [Mesh], "local recurrence" [Mesh], "Bladder cancer" [Mesh].

RESULTS

Several recent publications have led to the development of a nomogram that predicts the risk of LRR, in order to identify patients for which adjuvant radiotherapy could be beneficial. Several randomized trials seem to suggest a benefit of radiotherapy, in particular when combined with chemotherapy, in terms of reducing LRR, and may even improve overall survival, with good safety profile. However, there are many biases and the interest of adjuvant radiotherapy in urothelial carcinomas remains debated.

CONCLUSION

Prospective trials evaluating adjuvant radiotherapy with current techniques should be undertaken.

Effectiveness of postoperative radiotherapy after radical cystectomy for locally advanced bladder cancer

BACKGROUND

Local-regional failure (LF) for locally advanced bladder cancer (LABC) after radical cystectomy (RC) is common even with chemotherapy and is associated with high morbidity/mortality. Postoperative radiotherapy (PORT) can reduce LF and may enhance overall survival (OS) but has no defined role. We hypothesized that the addition of PORT would improve OS in LABC in a large nationwide oncology database.

METHODS

We identified ≥ pT3pN0-3M0 LABC patients in the National Cancer Database diagnosed 2004-2014 who underwent RC ± PORT. OS was calculated using Kaplan-Meier and Cox proportional hazards regression modeling was used to identify predictors of OS. Propensity matching was performed to match RC patients who received PORT vs those who did not.

RESULTS

15,124 RC patients were identified with 512 (3.3%) receiving PORT. Median OS was 20.0 months (95% CI, 18.2-21.8) for PORT vs 20.8 months (95% CI, 20.3-21.3) for no PORT (P = 0.178). In multivariable analysis, PORT was independently associated with improved OS: hazard ratio 0.87 (95% CI, 0.78-0.97); P = 0.008. A one-to-three propensity match yielded 1,858 patients (24.9% receiving PORT and 75.1% without). In the propensity-matched cohort, median OS was 19.8 months (95% CI, 18.0-21.6) for PORT vs 16.9 months (95% CI, 15.6-18.1) for no PORT (P = 0.030). In the propensity-matched cohort of urothelial carcinoma patients (N = 1,460), PORT was associated with improved OS for pT4, pN+, and positive margins (P < 0.01 all).

CONCLUSION

In this observational cohort, PORT was associated with improved OS in LABC. While the data should be interpreted cautiously, these results lend support to the use of PORT in selected patients with LABC, regardless of histology. Prospective trials of PORT are warranted.

Trimodality therapy for bladder cancer: modern management and future directions

PURPOSE OF REVIEW

This review examines both trimodality therapy (TMT) in the definitive management of bladder cancer as well as the use of adjuvant radiotherapy for bladder cancer with a specific focus on publications from the last 2 years.

RECENT FINDINGS

TMT is an effective management strategy for muscle invasive bladder cancer with outcomes similar to radical cystectomy. Effectiveness of this strategy exists in variant histologies and can be personalized with use of biomarkers. There is a role for adjuvant radiotherapy in locally advanced bladder cancer, especially in the age of improved imaging and modern radiotherapy techniques.

SUMMARY

This review should provide the reader data necessary to support use of TMT and adjuvant radiation therapy in their clinic.

Risk factors for loco-regional recurrence after radical cystectomy of muscle-invasive bladder cancer: A systematic-review and framework for adjuvant radiotherapy

BACKGROUND

Radical cystectomy (RC) associated with pelvic lymph node dissection (PLND) is the most common local therapy in the management of non-metastatic muscle invasive bladder cancer (MIBC). Loco-regional recurrence (LRR), however, remains a common and important therapeutic challenge associated with poor oncologic outcomes. We aimed to systematically review evidence regarding factors associated with LRR and to propose a framework for adjuvant radiotherapy (RT) in patients with MIBC.

METHODS

We performed this systematic review in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We searched the PubMed database for articles related to MIBC and associated treatments, published between January 1980 and June 2015. Articles identified by searching references from candidate articles were also included. We retrieved 1383 publications from PubMed and 34 from other sources. After an initial screening, a review of titles and abstracts, and a final comprehensive full text analysis of papers assessed for eligibility, a final consensus on 32 studies was obtained.

RESULTS

LRR is associated with specific patient-, tumor-, center- or treatment-related variables. LRR varies widely, occurring in as many as 43% of the cases and is strongly related to survival outcomes. While perioperative treatment does not impact on LRR, pathological factors such as pT, pN, positive margins status, extent of PLND, number of lymph nodes removed and/or invaded are correlated with LRR. Patients with pT3-T4a and/or positive lymph-nodes and/or limited pelvic lymph-node dissection and/or positive surgical margins have been distributed in LRR risk groups with accuracy.

CONCLUSIONS

LRR patterns are well-known and for selected patients, adjuvant treatments could target this event. Intrinsic tumor subtype may guide future criteria to define a personalized treatment strategy. Prospective trials evaluating safety and efficacy of adjuvant RT are ongoing in several countries.

Adjuvant Sandwich Chemotherapy Plus Radiotherapy vs Adjuvant Chemotherapy Alone for Locally Advanced Bladder Cancer After Radical Cystectomy: A Randomized Phase 2 Trial

Importance

Locoregional failure for patients with locally advanced bladder cancer (LABC) after radical cystectomy (RC) is common even with chemotherapy and is associated with high morbidity and mortality. Adjuvant radiotherapy (RT) can decrease locoregional failure but has not been studied in the chemotherapy era.

Objective

To investigate if adjuvant sequential RT plus chemotherapy can improve locoregional recurrence-free survival (LRFS) compared with adjuvant chemotherapy alone.

Design, Setting, and Participants

A randomized phase 3 trial was opened to compare adjuvant RT vs sequential chemotherapy plus RT after RC for LABC, but a third arm was added later as a randomized phase 2 trial to compare chemotherapy plus RT vs adjuvant chemotherapy alone, an emerging standard. The intent-to-treat phase 2 trial reported herein enrolled patients from December 2002 to July 2008. Data were analyzed from August 3, 2015, to January 6, 2016. Routine follow-up and surveillance pelvic computed tomographic (CT) scans every 6 months during the first 2 years were performed. The setting was an academic center. Patients with bladder cancer 70 years or younger having 1 or more risk factors (≥pT3b, grade 3, or positive nodes) with negative margins after radical cystectomy plus pelvic lymph node dissection were eligible. Patients had Eastern Cooperative Oncology Group performance status of 0 to 2, no evidence of distant metastases on CT scan of the abdomen and pelvis or on chest imaging, and adequate renal, hepatic, and hematologic function. Ninety-one percent (109 of 120) had ≥ pT3 disease.

Interventions

Chemotherapy plus RT included 2 cycles of gemcitabine (1000 mg/m2 intravenously on days 1, 8, and 15) and cisplatin (70 mg/m2 intravenously on day 2) before and after RT to 4500 cGy in 150 cGy twice-daily fractions over 3 weeks using 3-dimensional conformal techniques. Chemotherapy alone included 4 cycles of gemcitabine and cisplatin.

Main Outcome and Measure

Locoregional recurrence-free survival.

Results

The chemotherapy plus RT arm accrued 75 patients, and the chemotherapy-alone arm accrued 45 patients, with a weighted randomization to speed accrual. Fifty-three percent (64 of 120) had urothelial carcinoma, and 46.7% (56 of 120) had squamous cell carcinoma or other. The arms were balanced except for age (median, 52 vs 55 years; P = .04) and tumor size (mean, 4.9 vs 5.8 cm; P < .01), both favoring chemotherapy plus RT. Two-year outcomes and overall adjusted hazard ratios (HRs) for chemotherapy plus RT vs chemotherapy alone were 96% vs 69% (HR, 0.08; 95% CI, 0.02-0.39; P < .01) for LRFS, 68% vs 56% (HR, 0.53; 95% CI, 0.27-1.06; P = .07) for disease-free survival, and 71% vs 60% (HR, 0.61; 95% CI, 0.33-1.11; P = .11) for overall survival (OS). Five patients (7%) had RT-associated late grade 3 gastrointestinal tract adverse effects in the chemotherapy plus RT arm.

Conclusions and Relevance

Adjuvant chemotherapy plus RT was reasonably well tolerated and was associated with significant improvements in LRFS and marginal improvements in disease-free survival vs chemotherapy alone in LABC. The addition of adjuvant RT should be considered for LABC. This regimen warrants further study in phase 3 trials.

Trial Registration

clinicaltrials.gov Identifier: NCT01734798.

Adjuvant treatment following radical cystectomy for muscle-invasive urothelial carcinoma and variant histologies: Is there a role for radiotherapy?

Comprehensive molecular characterisation of muscle-invasive urothelial carcinoma and variant histological subtypes has led to the identification of recurrent driver mutations that are distinct in these aggressive subgroups of bladder cancer. While distant metastasis dominates as a pattern of relapse following radical cystectomy or chemoradiotherapy, loco-regional control rates are also suboptimal with single modality local treatment, and likewise, harbour equivocal implications on the long-term prognosis of patients. The role of adjuvant radiotherapy for optimising disease control within the pelvis is controversial, with limited evidence to support its efficacy. Herein, we present a stepwise review on adjuvant radiotherapy post-cystectomy; first, discussing the evidence to date supporting the concept that adjuvant radiotherapy is effective in targeting occult metastases within the pelvis, and adds to the benefits of adjuvant chemotherapy. Next, we outlined the principles underlying the definition of radiotherapy target volumes. To conclude, we addressed the need for appropriate patient stratification for treatment intensification, based on existing clinical models and novel molecular indices of aggression in muscle-invasive urothelial cancers and variant histological subtypes.

Oxymatrine inhibits proliferation of human bladder cancer T24 cells by inducing apoptosis and cell cycle arrest

Oxymatrine has been shown to exert an antitumor effect on several types of cancer cells. However, the role of oxymatrine in bladder cancer has not yet been evaluated. The present study was designed to investigate the potential anti-proliferative effect of oxymatrine on bladder cancer T24 cells and the possible mechanisms involved. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine cell growth, and the cell morphology was examined using hematoxylin and eosin staining, wrights' staining and electron microscopy. The caspase-3 and survivin mRNA and protein levels were assessed using reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. The expression of tumor protein p53 (p53), Bcl-2-associated X protein (Bax) and B-cell lymphoma 2 (Bcl-2) were analyzed using immunohistochemistry. Oxymatrine inhibited the proliferation of the T24 cells in a dose- and time-dependent manner. Oxymatrine also induced apoptosis and cell cycle arrest in the cells, in association with the upregulation of caspase-3 and Bax, and the downregulation of survivin, Bcl-2 and p53 expression. Overall, oxymatrine inhibits the proliferation of human bladder cancer cells by inducing apoptosis and cell cycle arrest via mechanisms that involve p53-Bax signaling and the downregulation of survivin expression.

Adjuvant radiotherapy after radical cystectomy for muscle-invasive bladder cancer: A retrospective multicenter study

Objectives

Radical cystectomy (RC) and pelvic lymph-node dissection (LND) is standard treatment for non-metastatic muscle-invasive urothelial bladder cancer (MIBC). However, loco-regional recurrence (LRR) is a common early event associated with poor prognosis. We evaluate 3-year LRR-free (LRRFS), metastasis-free (MFS) and overall survivals (OS) after adjuvant radiotherapy (RT) for pathological high-risk MIBC.

Material and methods

We retrospectively reviewed data from patients in 3 institutions. Inclusion criteria were MIBC, histologically-proven urothelial carcinoma treated by RC and adjuvant RT. Patients with conservative surgery were excluded. Outcomes were evaluated by Kaplan-Meier method. Acute toxicities were recorded according to CTCAE V4.0 scale.

Results

Between 2000 and 2013, 57 patients [median age 66.3 years (45–84)] were included. Post-operative pathological staging was ≤pT2, pT3 and pT4 in 16%, 44%, and 39%, respectively. PLND revealed 28% pN0, 26% pN1 and 42% pN2. Median number of lymph-nodes retrieved was 10 (2–33). Forty-eight patients (84%) received platin-based chemotherapy. For RT, clinical target volume 1 (CTV 1) encompassed pelvic lymph nodes for all patients. CTV 1 also included cystectomy bed for 37 patients (65%). CTV 1 median dose was 45 Gy (4–50). A boost of 16 Gy (5–22), corresponding to CTV 2, was administered for 30 patients, depending on pathological features. One third of patients received intensity-modulated RT. With median follow-up of 40.4 months, 8 patients (14%) had LRR. Three-year LRRFS, MFS and OS were 45% (95%CI 30–60), 37% (95%CI 24–51) and 49% (95%CI 33–63), respectively. Five (9%) patients had acute grade ≥3 toxicities (gastro-intestinal, genito-urinary and biological parameters). One patient died with intestinal fistula in a septic context.

Conclusions

Because of poor prognosis, an effective post-operative standard of care is needed for pathological high-risk MIBC. Adjuvant RT is feasible and may have oncological benefits. Prospective trials evaluating this approach with current RT techniques should be undertaken.

[Adjuvant radiotherapy for bladder cancer in patients with risk of locoregional recurrence: Who, what and how?]

Radical cystectomy with extended pelvic lymph node dissection remains the standard of care for non-metastatic muscle-invasive bladder cancer. Locoregional control is a key factor in the outcome of patients since it is related to overall survival, metastasis-free survival and specific survival. Locoregional recurrence rate is directly correlated to pathological results and the quality of lymphadenectomy. In addition, while pre- or postoperative chemotherapy improved overall survival, it showed no impact on locoregional recurrence-free survival. Several recent publications have led to the development of a nomogram that predicts the risk of locoregional recurrence, in order to identify patients for which adjuvant radiotherapy could be beneficial. International cooperative groups have then come together to provide the rational for adjuvant radiotherapy, reinforced by recent technical developments limiting toxicity, and to develop prospective studies to reduce the risk of relapse. The aim of this critical literature review is to provide an overview of the elements in favor of adjuvant radiation for patients treated for muscle-invasive bladder cancer.

The Rationale for Post-Operative Radiation in Localized Bladder Cancer

Local-regional recurrence for patients with ≥pT3 disease after radical cystectomy is a significant problem. Chemotherapy has not been shown to reduce the risk of local-regional recurrences in randomized prospective trials, and salvage therapies for local-regional failure are rarely successful. There is promising evidence, particularly from a recent Egyptian NCI trial, that radiation therapy plus chemotherapy can significantly reduce local recurrences compared to chemotherapy alone, and that this improvement in local-regional control may translate to meaningful improvements in disease-free and overall survival with acceptable toxicity. In light of the high rates of local failure following cystectomy for locally advanced disease and the progress that has been made in identifying patients at high risk of failure and the patterns of failure in the pelvis, the NCCN guidelines were revised in 2016 to include post-operative radiotherapy as an option to consider for patients with ≥pT3 disease. Despite advances in our understanding of the problem of local-regional failure after cystectomy and the potential role of adjuvant radiotherapy, the question of whether adjuvant radiotherapy should have a defined role for patients with locally advanced urothelial carcinoma has not yet been determined. The results of the NRG, European, Indian, and Egyptian trials on adjuvant radiotherapy are eagerly awaited. While none of these trials on their own may provide definitive conclusions, their aggregate outcomes will help clarify whether this treatment should have a role in the management of patients with locally advanced bladder cancer.

Adjuvant radiotherapy for pathological high-risk muscle invasive bladder cancer: time to reconsider?

Radical cystectomy with extended pelvic lymph-node dissection, associated with neo-adjuvant chemotherapy, remains the standard of care for advanced, non-metastatic muscle-invasive bladder cancer (MIBC). Loco-regional control is a key factor in the outcome of patients since it is related to overall survival (OS), disease-free survival (DFS) and cause-specific survival. The risk of loco-regional recurrence (LRR) is correlated to pathological factors as well as the extent of the lymphadenectomy. In addition, neither pre- nor post-operative chemotherapy have shown a clear impact on LRR-free survival. Several recent publications have led to the development of a nomogram predicting the risk of LRR, in order to identify patients most likely to benefit from adjuvant radiotherapy. Given the high risk of LRR for selected patients and improvements in radiation techniques that can reduce toxicity, there is a growing interest in adjuvant radiotherapy; international cooperative groups have come together to provide the rationale in favor of adjuvant radiotherapy. Clinical trials in order to reduce the risk of pelvic relapse are opened based on this optimizing patient selection. The aim of this critical literature review is to provide an overview of the rationale supporting the studies of adjuvant radiation for patients with pathologic high-risk MIBC.

Enumerating pelvic recurrence following radical cystectomy for bladder cancer: A Canadian multi-institutional study

INTRODUCTION

We aimed to enumerate the rate of pelvic recurrence following radical cystectomy at university-affiliated hospitals in Canada.

METHODS

Canadian, university-affiliated hospitals were invited to participate. They were asked to identify the first 10 consecutive patients undergoing radical cystectomy starting January 1, 2005, who had urothelial carcinoma stages pT3/T4 N0-2 M0. The first 10 consecutive cases starting January 1, 2005 who met these criteria were the patients submitted by that institution with information regarding tumour stage, age, number of nodes removed, and last known clinical status in regard to recurrence and patterns of failure.

RESULTS

Of the 111 patients, 80% had pT3 and 20% pT4 disease, with 62% being node-negative, 14% pN1, and 27% pN2; 57% had 10 or more nodes removed. Cumulative incidence of pelvic relapse was 40% among the entire group.

CONCLUSIONS

This review demonstrates a high rate of pelvic tumour recurrence following radical cystectomy for pT3/T4 urothelial cancer.

Development and Validation of Consensus Contouring Guidelines for Adjuvant Radiation Therapy for Bladder Cancer After Radical Cystectomy

PURPOSE

To develop multi-institutional consensus clinical target volumes (CTVs) and organs at risk (OARs) for male and female bladder cancer patients undergoing adjuvant radiation therapy (RT) in clinical trials.

METHODS AND MATERIALS

We convened a multidisciplinary group of bladder cancer specialists from 15 centers and 5 countries. Six radiation oncologists and 7 urologists participated in the development of the initial contours. The group proposed initial language for the CTVs and OARs, and each radiation oncologist contoured them on computed tomography scans of a male and female cystectomy patient with input from ≥1 urologist. On the basis of the initial contouring, the group updated its CTV and OAR descriptions. The cystectomy bed, the area of greatest controversy, was contoured by another 6 radiation oncologists, and the cystectomy bed contouring language was again updated. To determine whether the revised language produced consistent contours, CTVs and OARs were redrawn by 6 additional radiation oncologists. We evaluated their contours for level of agreement using the Landis-Koch interpretation of the κ statistic.

RESULTS

The group proposed that patients at elevated risk for local-regional failure with negative margins should be treated to the pelvic nodes alone (internal/external iliac, distal common iliac, obturator, and presacral), whereas patients with positive margins should be treated to the pelvic nodes and cystectomy bed. Proposed OARs included the rectum, bowel space, bone marrow, and urinary diversion. Consensus language describing the CTVs and OARs was developed and externally validated. The revised instructions were found to produce consistent contours.

CONCLUSIONS

Consensus descriptions of CTVs and OARs were successfully developed and can be used in clinical trials of adjuvant radiation therapy for bladder cancer.

Validating a Local Failure Risk Stratification for Use in Prospective Studies of Adjuvant Radiation Therapy for Bladder Cancer

PURPOSE

To inform prospective trials of adjuvant radiation therapy (adj-RT) for bladder cancer after radical cystectomy, a locoregional failure (LF) risk stratification was proposed. This stratification was developed and validated using surgical databases that may not reflect the outcomes expected in prospective trials. Our purpose was to assess sources of bias that may affect the stratification model's validity or alter the LF risk estimates for each subgroup: time bias due to evolving surgical techniques; trial accrual bias due to inclusion of patients who would be ineligible for adj-RT trials because of early disease progression, death, or loss to follow-up shortly after cystectomy; bias due to different statistical methods to estimate LF; and subgrouping bias due to different definitions of the LF subgroups.

METHODS AND MATERIALS

The LF risk stratification was developed using a single-institution cohort (n=442, 1990-2008) and the multi-institutional SWOG 8710 cohort (n=264, 1987-1998) treated with radical cystectomy with or without chemotherapy. We evaluated the sensitivity of the stratification to sources of bias using Fine-Gray regression and Kaplan-Meier analyses.

RESULTS

Year of radical cystectomy was not associated with LF risk on univariate or multivariate analysis after controlling for risk group. By use of more stringent inclusion criteria, 26 SWOG patients (10%) and 60 patients from the single-institution cohort (14%) were excluded. Analysis of the remaining patients confirmed 3 subgroups with significantly different LF risks with 3-year rates of 7%, 17%, and 36%, respectively (P<.01), nearly identical to the rates without correcting for trial accrual bias. Kaplan-Meier techniques estimated higher subgroup LF rates than competing risk analysis. The subgroup definitions used in the NRG-GU001 adj-RT trial were validated.

CONCLUSIONS

These sources of bias did not invalidate the LF risk stratification or substantially change the model's LF estimates.