The Rationale for Post-Operative Radiation in Localized Bladder Cancer

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.

The potential of ferroptosis combined with radiotherapy in cancer treatment

Ferroptosis is a new form of regulatory cell death that is closely related to the balance of redox reactions and the occurrence and development of cancer. There is increasing evidence that inducing ferroptosis in cells has great potential in the treatment of cancer. Especially when combined with traditional therapy, it can improve the sensitivity of cancer cells to traditional therapy and overcome the drug resistance of cancer cells. This paper reviews the signaling pathways regulating ferroptosis and the great potential of ferroptosis and radiotherapy (RT) in cancer treatment and emphasizes the unique therapeutic effects of ferroptosis combined with RT on cancer cells, such as synergy, sensitization and reversal of drug resistance, providing a new direction for cancer treatment. Finally, the challenges and research directions for this joint strategy are discussed.

Challenges and opportunities in the management of non-urothelial bladder cancers

Urothelial carcinoma accounts for approximately 90% of all bladder cancer diagnoses. Localized, muscle-invasive disease is often managed with a multidisciplinary approach including either neoadjuvant chemotherapy (NAC) followed by radical cystectomy or concurrent chemoradiation, whereas multiple immunotherapies and novel antibody drug conjugates have recently joined platinum-based chemotherapy as standard of care therapy for metastatic disease. However, the clinical trials leading to these standards often require majority if not complete urothelial histology for eligibility. As many as one quarter of patients diagnosed with bladder cancer will have either divergent differentiation of their urothelial carcinoma or an alternate epithelial tumor such as squamous cell carcinoma, adenocarcinoma, or small cell carcinoma; even more rare are non-epithelial tumors such as sarcoma. The rarity of these diseases and their general exclusion from treatment within prospective clinical trials has created a challenging situation where treatment plans are often derived from case series or extrapolated from other disease types and outcomes are poor compared to pure urothelial carcinoma. In this review, we summarize the existing data on the diagnosis and treatment of epithelial, non-urothelial bladder cancers including adenocarcinoma, squamous cell carcinoma, and small cell carcinoma in their localized and advances stages. We will also review the current clinical trial landscape investigating novel approaches to these diseases.

Adjuvant chemotherapy plus radiotherapy versus chemotherapy alone for locally advanced bladder cancer after radical cystectomy

BACKGROUND: Survival with locally advanced bladder cancer (LABC) following radical cystectomy (RC) remains poor. Although adjuvant chemotherapy (AC) is standard of care, one small, randomized trial has suggested a potential survival benefit when combined with post-operative radiotherapy (PORT). OBJECTIVE: We examined the association of AC + PORT with overall survival (OS) in patients with LABC after RC. METHODS: Using a prior phase 2 trial to inform design, we conducted observational analyses to emulate a hypothetical target trial of patients aged 18–79 years with pT3-4 Nany M0 or pTany N1-3 M0 urothelial bladder carcinoma following RC who were treated with AC (multiagent chemotherapy within 3 months of RC) with or without PORT (≥45 Gy to the pelvis) from 2006–2015 in the NCDB. Patients who received preoperative chemotherapy or radiotherapy were excluded. The associations of treatment with OS were evaluated using multivariable Cox regression. RESULTS: 1,684 patients were included, with 66 receiving AC + PORT and 1,618 AC alone. Compared to patients treated with AC alone, those treated with AC + PORT were more likely to have pT4 disease (52% vs 26% ; p <  0.01), positive surgical margins (44% vs 17% ; p <  0.01), and be treated at a non-academic facility (75% vs 53% ; p <  0.01). Crude 5-year OS was 19% for AC + PORT versus 36% for AC alone (p = 0.01). Adjusted 5-year OS was 33% for AC + PORT versus 36% for AC alone (p = 0.49). After adjusting for baseline characteristics including pathologic features, AC + PORT was not associated with improved OS compared to AC alone (HR 1.11; 95% CI 0.82–1.51). CONCLUSIONS: Although infrequently utilized, the addition of radiotherapy to AC is not associated with improved OS in LABC. These results highlight the need for prospective trials to better define the potential benefits from PORT with regard to symptomatic progression and oncologic outcomes.

Comparison of adjuvant chemoradiotherapy versus radiotherapy in early-stage cervical cancer patients with intermediate-risk factors: A systematic review and meta-analysis

The presence of intermediate risk factors reduces the predictability of radical hysterectomy, demanding the use of adjuvant therapy for treatment of Early stage cervical cancer (ESCC) patients. Adjuvant radiotherapy (RT) and chemoradiotherapy (CRT) has been widely used with varied efficacy and safety issues. Therefore, the aim of this systematic review and meta-analysis was to update the available evidence and assess the effect of post-surgical adjuvant RT versus adjuvant CRT on survival rate and complications/toxicities in management of ESCC patients with intermediate risk factors. PubMed, EMBASE and Web of Science (WOS) and CENTRAL were searched using a combination of relevant keywords. All studies comparing outcomes of adjuvant RT versus CRT in ESCC patients with intermediate-risk factors in terms of recurrence free survival (RFS), overall survival (OS) and toxicities/complications were included. Both qualitative and quantitative analysis was carried out. The risk of bias assessment was done using Newcastle-Ottawa scale (NOS) for retrospective cohort studies and Cochrane risk of bias assessment tool was used for randomized clinical trials. Eleven retrospective cohort studies and two randomized clinical trials were included in this review. Adjuvant CRT was found to have better RFS with ESCC patients with multiple intermediate risk factors with OR 3.11 95% CI [1.04, 4.99], p < 0.0001; i2 = 6%. However, similar benefit was observed between both regimens in presence of a single intermediate risk factor OR 1.80 95% CI [0.96, 3.36], p = 0.07; i2 = 0%. Grade 3 or 4 haematological toxicity among patients receiving post-surgical adjuvant RT versus adjuvant CRT showed increased association of toxicity with adjuvant CRT with OR 7.73 95%CI [3.40, 17.59], p < 0.0001; i2 = 62%. Adjuvant CRT shows favourable RFS and OS in ESCC patients with multiple intermediate risk factors. CRT also showed greater incidence of grade 3 or 4 haematological and non-haematiological toxicity, however, the same could be well tolerated when used within the recommended dosage.

Oncologic Impact and Safety of Pre-Operative Radiotherapy in Localized Prostate and Bladder Cancer: A Comprehensive Review from the Cancerology Committee of the Association Française d'Urologie

Simple Summary

Radiotherapy may have an interesting role of reinforcing the loco-regional control of cancer, in addition to surgery, when used as a preoperative treatment. This sequence has demonstrated its efficacy and safety in various malignancies, but no strong data exist in the era of uro-oncology. In this review article, we aim to highlight the potential usefulness of preoperative radiotherapy in prostate and muscle-invasive bladder cancer, aiming to enhance pathological response and local control and to prevent intraoperative tumor seeding. We also emphasize the need for further clinical studies assessing the functional safety of subsequent surgical procedures in a competitive context of new systemic agents that have proven to demonstrate a survival benefit in locally advanced urologic cancers.

Abstract

Preoperative radiotherapy (RT) is commonly used for the treatment of various malignancies, including sarcomas, rectal, and gynaecological cancers, but it is preferentially used as a competitive treatment to radical surgery in uro-oncology or as a salvage procedure in cases of local recurrence. Nevertheless, preoperative RT represents an attractive strategy to prevent from intraoperative tumor seeding in the operative field, to sterilize microscopic extension outside the organ, and to enhance the pathological and/or imaging tumor response rate. Several clinical works support this research field in uro-oncology. In this review article, we summarized the oncologic impact and safety of preoperative RT in localized prostate and muscle-invasive bladder cancer. Preliminary studies suggest that both modalities can be complementary as initial primary tumor treatments and that a pre-operative radiotherapy strategy could be beneficial in a well-defined population of patients who are at a very high-risk of local relapse. Future prospective trials are warranted to evaluate the oncologic benefit of such a combination of local treatments in addition to new life-prolonging systemic therapies, such as immunotherapy, and new generation hormone therapies. Moreover, the safety and the feasibility of salvage surgical procedures due to non-response or local recurrence after pelvic RT remain poorly evaluated in that context.

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.

Potential Alternatives to Conventional Cancer Therapeutic Approaches: The Way Forward

onventional cancer therapeutic approaches broadly include chemotherapy, radiation therapy and surgery. These established approaches have evolved over several decades of clinical experience. For a complex disease like cancer, satisfactory treatment remains an enigma for the simple fact that the causal factors for cancer are extremely diverse. In order to overcome existing therapeutic limitations, consistent scientific endeavors have evolved several potential therapeutic approaches, majority of which focuses essentially on targeted drug delivery, minimal concomitant ramification, and selective high cytotoxicity. The current review focuses on highlighting some of these potential alternatives that are currently in various stages of in vitro, in vivo, and clinical trials. These include physical, chemical and biological entities that are avidly being explored for therapeutic alternatives. Some of these entities include suicide gene, micro RNA, modulatory peptides, ultrasonic waves, free radicals, nanoparticles, phytochemicals, and gene knockout, and stem cells. Each of these techniques may be exploited exclusively and in combination with conventional therapeutic approaches thereby enhancing the therapeutic efficacy of the treatment. The review intends to briefly discuss the mechanism of action, pros, and cons of potential alternatives to conventional therapeutic approaches.

Neobladder and ablative pelvic radiotherapy: still a taboo?

The presence of a neobladder constitutes a limitation for the radiation oncologist, as there is no clear evidence about its tolerance to radiotherapy (RT). The limited literature only concerns the conventional postoperative treatment in patients with bladder cancer after cystectomy. Here we report a case of a patient with neobladder who underwent a stereotactic RT for a pelvic recurrence of disease, with response to treatment and no toxicity to the neobladder. This case represents a promising example of the chance to perform RT with ablative intent, using advanced techniques, even on lesions close to the neobladder.

A phase II study of neoadjuvant chemotherapy followed by organ preservation in patients with muscle-invasive bladder cancer

Objective

Conservative approaches in muscle-invasive bladder cancer (MIBC) have been evolved to avoid aggressive surgery, but are limited to elderly, frail, and patients medically unfit for surgery. Our study aimed to assess the response rate of neoadjuvant chemotherapy (NACT) before radiotherapy (RT) in MIBC patients.

Methods

Forty patients with urothelial carcinoma of stage T2–T4a, N0, M0 were enrolled between November 2013 and November 2015, and treated with three cycles of NACT with gemcitabine-cisplatin. Post-NACT response was assessed using Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Patients who achieved complete response (CR) and partial response (PR) >50% were treated with radical RT, and those who had PR <50%, stable disease (SD), and progressive disease (PD) underwent radical cystectomy (RC). Survival analysis was done with Kaplan-Meier method and point-to-time events were analyzed with Cox-proportional hazards regression model.

Results

After NACT, 35 (87.5%) patients achieved either PR >50% or CR, and were treated with RT. Five (12.5%) patients who had PR <50%, SD, or PD underwent RC. All patients who received radiation showed CR after 6 weeks. Median follow-up was 43 months (range: 10–66 months) and median overall survival (OS) was not reached. Three-year OS, local control, and disease-free survival were 70.1%, 60.9%, 50.6%, respectively, and 50% of patients preserved their functioning bladder. Three-year OS rate was 88.9% in patients who achieved CR to NACT, 73.1% in patients with PR ≥50% and 40% in patients with PR <50%.

Conclusion

NACT followed by RT provides a high probability of local response with bladder preservation in CR patients. Appropriate use of this treatment regimen in carefully selected patients may omit the need for morbid surgery.

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.

Locoregional recurrence after cystectomy in muscle invasive bladder cancer: Implications for adjuvant radiotherapy

PURPOSE

We report the patterns of locoregional recurrence (LRR) in muscle invasive bladder cancer (MIBC), and propose a risk stratification to predict LRR for optimizing the indication for adjuvant radiotherapy.

MATERIALS AND METHODS

The study included patients of urothelial MIBC who underwent radical cystectomy with standard perioperative chemotherapy between 2013 and 2019. Recurrences were classified into local and/or cystectomy bed, regional, systemic, or mixed. For risk stratification modelling, T stage (T2, T3, T4), N stage (N0, N1/2, N3) and lymphovascular invasion (LVI positive or negative) were given differential weightage for each patient. The cohort was divided into low risk (LR), intermediate risk (IR) and high risk (HR) groups based on the cumulative score.

RESULTS

Of the 317 patients screened, 188 were eligible for the study. Seventy patients (37.2%) received neoadjuvant chemotherapy (NACT) while 128 patients (68.1%) had T3/4 disease and 66 patients (35.1%) had N+ disease. Of the 55 patients (29%) who had a recurrence, 31 (16%) patients had a component of LRR (4% cystectomy bed, 11.5% regional 0.5% locoregional). The median time to LRR was 8.2 (IQR 3.3-18.8) months. The LR, IR and HR groups for LRR based on T, N and LVI had a cumulative incidence of 7.1%, 21.6%, and 35% LRR, respectively. The HR group was defined as T3, N3, LVI positive; T4 N1/2, LVI positive; and T4, N3, any LVI. The odds ratio for LRR was 3.37 (95% CI 1.16-9.73, P = 0.02) and 5.27 (95% CI 1.87-14.84, P = 0.002) for IR and HR respectively, with LR as reference.

CONCLUSION

LRR is a significant problem post radical cystectomy with a cumulative incidence of 35% in the HR group. The proposed risk stratification model in our study can guide in tailoring adjuvant radiotherapy in MIBC.

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.

A propensity analysis comparing definitive chemo-radiotherapy for muscle-invasive squamous cell carcinoma of the bladder vs. urothelial carcinoma of the bladder using the National Cancer Database

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Limited information is known about treatment outcomes for squamous cell carcinoma of the bladder (SqCC).

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Treatment for SqCC is extrapolated from urothelial carcinoma.

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Outcomes of chemoRT for SqCC are very limited.

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Following chemoRT, patients with SqCC do worse than counterparts with urothelial carcinoma.

Introduction

Squamous cell carcinoma (SqCC) is the second most common histology of primary bladder cancer, but still very limited information is known about its treatment outcomes. Most bladder cancer trials have excluded SqCC, and the current treatment paradigm for localized SqCC is extrapolated from results in urothelial carcinoma (UC). In particular, there is limited data on the efficacy of definitive chemo-radiotherapy (CRT). In this study, we compare overall survival outcomes between SqCC and UC patients treated with definitive CRT.

Materials/methods

We queried the National Cancer Database (NCDB) for muscle-invasive (cT2-T4 N0 M0) bladder cancer patients diagnosed from 2004 to 2013 who underwent concurrent CRT. Propensity matching was performed to match patients with SqCC to those with UC. OS was analyzed using the Kaplan-Meier survival method, and the log-rank test and Cox regression were used for analyses.

Results

3332 patients met inclusion criteria of which 79 (2.3%) had SqCC. 73.4% of SqCC patients had clinical T2 disease compared to 82.5% of UC patients. Unadjusted median OS for SqCC patients was 15.6 months (95% CI, 11.7–19.6) versus 29.1 months (95% CI, 27.5–30.7) for those with UC (P < 0.0001). On multivariable analysis, factors associated with worse OS included: SqCC histology [HR: 1.53 (95% CI, 1.19–1.97); P = 0.001], increasing age [HR: 1.02 (95% CI, 1.02–1.03); P < 0.0001], increasing clinical T-stage [HR: 1.21 (95% CI, 1.13–1.29); P < 0.0001], and Charlson-Deyo comorbidity index [HR: 1.26 (95% CI, 1.18–1.33); P < 0.0001]. Seventy-seven SqCC patients were included in the propensity-matched analysis (154 total patients) with a median OS for SqCC patients of 15.1 months (95% CI, 11.1–18.9) vs. 30.4 months (95% CI, 19.4–41.4) for patients with UC (P = 0.013).

Conclusions

This is the largest study to-date assessing survival outcomes for SqCC of the bladder treated with CRT. In this study, SqCC had worse overall survival compared to UC patients. Histology had a greater impact on survival than increasing T-stage, suggesting that histology should be an important factor when determining a patient’s treatment strategy and that treatment intensification in this subgroup may be warranted.

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.

The Role of Adjuvant Radiation Therapy in Locally Advanced Bladder Cancer

Background:

The standard of care for locally advanced bladder cancer (LABC) is neoadjuvant chemotherapy followed by cystectomy. However, the role of adjuvant therapy for locally advanced bladder cancer is unclear.

Objective:

The purpose of this study was to evaluate the outcomes of adjuvant radiation therapy (RT) for patients with LABC, and to determine which risk factors best predict for patients who may best benefit from adjuvant RT.

Methods:

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

Results:

Altogether, 1,646 patients met inclusion criteria; 59 (3.6%) patients received adjuvant RT, while 1,587 (96.4%) were observed. Patients treated with adjuvant RT were more likely to be female, have positive surgical margins, and receive treatment at a non-academic facility. There was no difference in median overall survival (OS) between patients treated with RT when compared to patients observed (17.7 months vs. 23.5 months; p = 0.085). However, an improvement in median OS with the use of adjuvant RT was observed among patients with positive surgical margins (20.3 months vs. 13.1 months; p = 0.032). 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 radiotherapy in patients with locally advanced bladder cancer, use of RT was not associated with OS in all patients, while RT was associated with improvemed OS among patients with positive surgical margins. Prospective studies are recommended to confirm these findings.

Therapeutic strategies for organ-confined and non-organ-confined bladder cancer after radical cystectomy

INTRODUCTION

In patients with muscle invasive or Bacillus Calmette-Guérin refractory urothelial carcinoma of the urinary bladder (UCUB) radical cystectomy represents the standard of care. However, a proportion of patients experience disease progression, local recurrence and/or metastatic disease. Areas covered: This review provides an overview of available therapeutic strategies after radical cystectomy and examines ongoing clinical trials including cytotoxic chemotherapy and immunotherapy. Expert commentary: Cytotoxic chemotherapy offers limited benefit in UCUB patients. However, the recent introduction of immunotherapy provides new hope for durable responses or possibly complete cures.

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.

Cancer Radiosensitizers

Radiotherapy (RT) is a mainstay treatment for many types of cancer, although it is still a large challenge to enhance radiation damage to tumor tissue and reduce side effects to healthy tissue. Radiosensitizers are promising agents that enhance injury to tumor tissue by accelerating DNA damage and producing free radicals. Several strategies have been exploited to develop highly effective and low-toxicity radiosensitizers. In this review, we highlight recent progress on radiosensitizers, including small molecules, macromolecules, and nanomaterials. First, small molecules are reviewed based on free radicals, pseudosubstrates, and other mechanisms. Second, nanomaterials, such as nanometallic materials, especially gold-based materials that have flexible surface engineering and favorable kinetic properties, have emerged as promising radiosensitizers. Finally, emerging macromolecules have shown significant advantages in RT because these molecules can be combined with biological therapy as well as drug delivery. Further research on the mechanisms of radioresistance and multidisciplinary approaches will accelerate the development of radiosensitizers.