Adjuvant Radiation for Locally Advanced Bladder Cancer? A Question Worth Asking

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.

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.

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.

The role of adjuvant chemotherapy in locally advanced bladder cancer

PURPOSE

The standard of care for locally advanced bladder cancer (LABC) is neoadjuvant chemotherapy followed by cystectomy. However, the role of adjuvant therapy is unclear. The purpose of this study was to evaluate the outcomes of adjuvant chemotherapy for patients with LABC following neoadjuvant chemotherapy and cystectomy, and to determine whether select patients may benefit from adjuvant chemotherapy.

METHODS

The National Cancer Data Base (NCDB) was queried (2004-2013) for patients with newly diagnosed pT3-4N0-3M0 bladder cancer that received neoadjuvant chemotherapy and cystectomy. Patients were divided into two groups based on the adjuvant therapy they received: chemotherapy alone or observation. Statistics included multivariable logistic regression to determine factors predictive of receiving adjuvant chemotherapy, Kaplan-Meier analysis to evaluate overall survival (OS) and Cox proportional hazards modeling to determine variables associated with OS.

RESULTS

Altogether, 2592 patients met inclusion criteria; 901 (34.8%) patients received adjuvant chemotherapy, while 1691 (65.2%) were observed. Patients treated with adjuvant chemotherapy were more likely to have positive margins were younger and more likely to receive treatment at a nonacademic facility. There was no difference in median OS between patients treated with or without adjuvant chemotherapy (22.6 vs. 21.1 months; p = .267). However, a longer median OS was observed with the use of adjuvant chemotherapy was observed among patients with N2-3 disease (17.5 vs. 14.4 months; p = .005) and positive surgical margins (16.7 vs. 12.2 months; p = .025). On multivariate analysis, advancing age, pT4 stage, positive N stage, positive margins and lower socioeconomic status were associated with worse OS.

CONCLUSIONS

In the largest study to date evaluating efficacy of adjuvant chemotherapy, while no difference in OS was observed for adjuvant chemotherapy in all patients, a longer OS was observed among patients with N2-3 disease or with positive surgical margins. Prospective studies are recommended to further evaluate these findings.

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.

Bladder cancer: Present and future

Bladder cancer has a high incidence and involves high associated morbidity and mortality. Since its initial clinical suspicion, early diagnostic confirmation and multimodal treatment involve different medical specialties. For this reason, we consider it important to spread the current consensus for its management. Recent advances in immunology and Chemotherapy make it necessary to expose and reflect on future perspectives.

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.

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.