Beyond surgery: bladder preservation and the role of systemic treatment in localised muscle-invasive bladder cancer.

Over the last two to three decades the non-surgical curative management of bladder cancer has significantly progressed. Increasing evidence supports the use of bladder preservation as an alternative to radical cystectomy (RC) for localised muscle-invasive bladder cancer (MIBC). Radiosensitisation with chemotherapy or hypoxia modification improves the efficacy of radiotherapy. Systemic treatments play an important role in the management of localised MIBC with the benefit of neoadjuvant chemotherapy prior to radical treatment well established. The use of immune checkpoint inhibitors (ICIs) in the radical treatment of bladder cancer, their safe combination with radical radiotherapy regimens and whether the addition of ICIs improve rates of cure are outstanding questions beginning to be answered by ongoing clinical trials. In this narrative review, we discuss the current evidence for bladder preservation and the role of systemic treatments for localised MIBC.

A hypoxia biomarker does not predict benefit from giving chemotherapy with radiotherapy in the BC2001 randomised controlled trial.

BACKGROUND: BC2001 showed combining chemotherapy (5-FU + mitomycin-C) with radiotherapy improves loco-regional disease-free survival in patients with muscle-invasive bladder cancer (MIBC). We previously showed a 24-gene hypoxia-associated signature predicted benefit from hypoxia-modifying radiosensitisation in BCON and hypothesised that only patients with low hypoxia scores (HSs) would benefit from chemotherapy in BC2001. BC2001 allowed conventional (64Gy/32 fractions) or hypofractionated (55Gy/20 fractions) radiotherapy. An exploratory analysis tested an additional hypothesis that hypofractionation reduces reoxygenation and would be detrimental for patients with hypoxic tumours. METHODS: RNA was extracted from pre-treatment biopsies (298 BC2001 patients), transcriptomic data generated (Affymetrix Clariom-S arrays), HSs calculated (median expression of 24-signature genes) and patients stratified as hypoxia-high or -low (cut-off: cohort median). PRIMARY ENDPOINT: invasive loco-regional control (ILRC); secondary overall survival. FINDINGS: Hypoxia affected overall survival (HR = 1.30; 95% CI 0.99-1.70; p = 0.062): more uncertainty for ILRC (HR = 1.29; 95% CI 0.82-2.03; p = 0.264). Benefit from chemotherapy was similar for patients with high or low HSs, with no interaction between HS and treatment arm. High HS associated with poor ILRC following hypofractionated (n = 90, HR 1.69; 95% CI 0.99-2.89 p = 0.057) but not conventional (n = 207, HR 0.70; 95% CI 0.28-1.80, p = 0.461) radiotherapy. The finding was confirmed in an independent cohort (BCON) where hypoxia associated with a poor prognosis for patients receiving hypofractionated (n = 51; HR 14.2; 95% CI 1.7-119; p = 0.015) but not conventional (n = 24, HR 1.04; 95% CI 0.07-15.5, p = 0.978) radiotherapy. INTERPRETATION: Tumour hypoxia status does not affect benefit from BC2001 chemotherapy. Hypoxia appears to affect fractionation sensitivity. Use of HSs to personalise treatment needs testing in a biomarker-stratified trial. FUNDING: Cancer Research UK, NIHR, MRC.

Hypofractionation: less is more?

One third of patients with bladder cancer present with muscle invasive bladder cancer (MIBC) which has a poor prognosis. International guidelines for the management of MIBC recommend radical cystectomy or bladder-preserving treatment based on radical radiotherapy with a form of radiosensitisation. In the UK, both conventional fractionation with 64 Gy in 32 fractions and hypofractionation with 55 Gy in 20 fractions are standard of care options with the choice varying between centres. A meta-analysis of individual patients with locally advanced bladder cancer from two UK multicentre phase 3 trials was published recently. This study evaluated the non-inferiority of a hypofractionated schedule compared to a conventional regime. This analysis confirmed the non-inferiority of the hypofractionated regimen, and noted superior locoregional control. We discuss the relevance of these findings to current practice while considering the radiobiology of hypofractionation, the role of systemic therapies and radiosensitisation, as well as the socioeconomic benefits.

Long-Term Outcomes of Radical Radiation Therapy with Hypoxia Modification with Biomarker Discovery for Stratification: 10-Year Update of the BCON (Bladder Carbogen Nicotinamide) Phase 3 Randomized Trial (ISRCTN45938399).

PURPOSE: Many muscle-invasive bladder cancers are hypoxic, which limits the efficacy of radiation therapy. Hypoxia modification using carbogen and nicotinamide has been tested in a phase 3 trial, Bladder Carbogen Nicotinamide. We present mature follow-up data with biomarker predictions of outcomes. METHODS AND MATERIALS: Bladder Carbogen Nicotinamide is a prospective, phase 3, multicenter, randomized, 2-arm, nonblinded clinical trial. Participants were randomized to receive radical radiation therapy (RT; control arm) alone or with the addition of carbogen (98% O2; 2% CO2) and nicotinamide (CON). Patients with muscle-invasive or high-grade non-muscle invasive bladder cancer were included. Tumor tissue was collected at entry and was analyzed for tumor necrosis, hypoxia (24-gene signature), and basal and luminal tumor molecular subtypes. Overall survival (OS) and disease-free survival and relationships with biomarker status outcomes are analyzed using multivariable Cox regression and log-rank analysis. RESULTS: We analyzed 333 patients with a median follow-up of 10.3 years. The 10-year OS rates were 30% (95% confidence interval [CI], 0.23-0.39) in RT + CON patients and 24% (95% CI, 0.18-0.33) in the RT-alone patients (hazard ratio [HR], 0.80; 95% CI, 0.61-1.04; P = .08). The greatest benefit from CON was seen in patients with tumor necrosis (n = 79; 5-year OS, 53% vs. 33% in patients without tumor necrosis; HR, 0.59; 95% CI, 0.36-0.99; P = .04). Cases with a high hypoxia gene score (n = 75) had a 5-year OS rate of 51%, compared to 34% for a low score (HR, 0.64; 95% CI, 0.38-1.08; P = .09); those with the basal molecular subtype (n = 70) had a 5-year OS rate of 58%, compared to 38% for those with the luminal subtype (HR, 0.58; 95% CI, 0.32-1.06; P = .08). CONCLUSIONS: Although the improvement in long-term OS in the whole population is not statistically significant, patients selected by necrosis and high hypoxia gene score benefitted from hypoxia modification.

Hypofractionated radiotherapy in locally advanced bladder cancer: an individual patient data meta-analysis of the BC2001 and BCON trials.

BACKGROUND: Two radiotherapy fractionation schedules are used to treat locally advanced bladder cancer: 64 Gy in 32 fractions over 6·5 weeks and a hypofractionated schedule of 55 Gy in 20 fractions over 4 weeks. Long-term outcomes of these schedules in several cohort studies and case series suggest that response, survival, and toxicity are similar, but no direct comparison has been published. The present study aimed to assess the non-inferiority of 55 Gy in 20 fractions to 64 Gy in 32 fractions in terms of invasive locoregional control and late toxicity in patients with locally advanced bladder cancer. METHODS: We did a meta-analysis of individual patient data from patients (age ≥18 years) with locally advanced bladder cancer (T1G3 [high-grade non-muscle invasive] or T2-T4, N0M0) enrolled in two multicentre, randomised, controlled, phase 3 trials done in the UK: BC2001 (NCT00024349; assessing addition of chemotherapy to radiotherapy) and BCON (NCT00033436; assessing hypoxia-modifying therapy combined with radiotherapy). In each trial, the fractionation schedule was chosen according to local standard practice. Co-primary endpoints were invasive locoregional control (non-inferiority margin hazard ratio [HR]=1·25); and late bladder or rectum toxicity, assessed with the Late Effects Normal Tissue Task Force-Subjective, Objective, Management, Analytic tool (non-inferiority margin for absolute risk difference [RD]=10%). If non-inferiority was met for invasive locoregional control, superiority could be considered if the 95% CI for the treatment effect excluded the null effect (HR=1). One-stage individual patient data meta-analysis models for the time-to-event and binary outcomes were used, accounting for trial differences, within-centre correlation, randomised treatment received, baseline variable imbalances, and potential confounding from relevant prognostic factors. FINDINGS: 782 patients with known fractionation schedules (456 from the BC2001 trial and 326 from the BCON trial; 376 (48%) received 64 Gy in 32 fractions and 406 (52%) received 55 Gy in 20 fractions) were included in our meta-analysis. Median follow-up was 120 months (IQR 99-159). Patients who received 55 Gy in 20 fractions had a lower risk of invasive locoregional recurrence than those who received 64 Gy in 32 fractions (adjusted HR 0·71 [95% CI 0·52-0·96]). Both schedules had similar toxicity profiles (adjusted RD -3·37% [95% CI -11·85 to 5·10]). INTERPRETATION: A hypofractionated schedule of 55 Gy in 20 fractions is non-inferior to 64 Gy in 32 fractions with regard to both invasive locoregional control and toxicity, and is superior with regard to invasive locoregional control. 55 Gy in 20 fractions should be adopted as a standard of care for bladder preservation in patients with locally advanced bladder cancer. FUNDING: Cancer Research UK.

Palliative Radiation Therapy in Bladder Cancer-Importance of Patient Selection: A Retrospective Multicenter Study.

PURPOSE: To investigate the effectiveness of palliative pelvic radiation therapy (PRT) in patients with bladder cancer and identify factors associated with treatment outcome. METHODS AND MATERIALS: Patients with bladder cancer receiving PRT were identified retrospectively from 2 cancer centers between 2014 and 2017. Patients were stratified by age, stage, performance status, comorbidities, previous chemotherapy, previous radiation therapy, and radiation therapy protocol. Patients were followed up at 6 weeks after radiation therapy (RT). Median overall survival (mOS) from the last fraction of RT was calculated. Death within 30 days of RT or noncompletion of treatment were considered as futile treatment. RESULTS: Two hundred forty-one patients were identified as receiving PRT. A variety of RT protocols were used: 8 Gy in 1 fraction (11%), 21 Gy in 3 fractions (15%), 20 Gy in 5 fractions (18%), 36 Gy in 6 fractions (36%), and 27.5 to 30 Gy in 8 to 10 fractions (18%). Thirty-eight percent of patients were of poor performance status (Eastern Cooperative Oncology Group performance status ≥3), and 46.5% had significant comorbidities (Adult Comorbidity Evaluation-27 ≥2). The mOS from the last fraction of RT was 153 days (0-1289 days). The 30-day mortality after radiation therapy was 18% (n = 44), and the rate of incomplete planned radiation therapy treatment was 14% (n = 33). First follow-up information was available in 62% (n = 150) of patients. Median time to this follow-up was 49 days (14-238 days). At first follow-up at about 6 weeks after the last fraction of radiation therapy, symptoms were reported in 150 of 200 (75%) living patients; 80 of 150 (53%) patients reported improvement in symptoms after treatment. There were significant differences in mOS with stage, performance status, and comorbidities. CONCLUSIONS: One in 4 patients either did not complete the planned RT course or died within 30 days of treatment. These patients were unlikely to have received maximal benefit from treatment but may have experienced side effects, making treatment futile. Patients with good performance status and earlier stage disease survived longer. Patient selection and comprehensive assessment are crucial in selecting appropriate patients for treatment.

Organ preservation in bladder cancer: an opportunity for truly personalized treatment.

Radical treatment of many solid tumours has moved from surgery to multimodal organ preservation strategies combining systemic and local treatments. Trimodality bladder-preserving treatment (TMT) comprises maximal transurethral resection of the bladder tumour followed by radiotherapy and concurrent radiosensitizing treatment, thereby sparing the urinary bladder. From the patient's perspective, the choice of maintaining quality of life without a negative effect on the chances of cure and long-term survival is attractive. In muscle-invasive bladder cancer (MIBC), the evidence shows comparable clinical outcomes between patients undergoing radical cystectomy and TMT. Despite this evidence, many patients continue to be offered radical surgery as the standard-of-care treatment. Improvements in radiotherapy techniques with adaptive radiotherapy and advances in imaging translate to increases in the accuracy of treatment delivery and reductions in long-term toxicities. With the advent of novel biomarkers promising improved prediction of treatment response, stratification of patients for different treatments on the basis of tumour biology could soon be a reality. The future of oncological treatment lies in personalized medicine with the combination of technological and biological advances leading to truly bespoke management for patients with MIBC.

Radiation Necrosis - A Growing Problem in a Case of Brain Metastases Following Whole Brain Radiotherapy and Stereotactic Radiosurgery.

Stereotactic radiosurgery (SRS) provides excellent control in the treatment of brain metastases (BM). The use of newer, targeted and immunotherapy treatments have resulted in improved overall survival in patients even with an extensive metastatic disease. Hence, it is increasingly important to consider the potential for late toxicities like radiation-induced necrosis (RN) of the brain. We present a case of a patient with stage IV anaplastic lymphoma kinase (ALK) positive adenocarcinoma of the lung who underwent stereotactic radiosurgery to her brain metastases and received targeted treatment. While her intracranial and extracranial disease remained well controlled, we discuss the radiation-induced necrosis she suffered as a result of the treatment, the related diagnostic dilemma involved, and the subsequent management of this late toxicity of stereotactic radiosurgery.

Comparing Clinical Outcomes for Radium-223: Do Older Patients Do Worse?

PURPOSE: To examine the clinical benefits and toxicities of 223Ra in 2 different age groups of patients with castrate-resistant prostate cancer. METHODS AND MATERIALS: This was a retrospective study of patients treated with 223Ra in 2 tertiary centers. Patients were divided into 2 different groups based on their age (≥72 years old and <72 years old). Treatment toxicities were graded according to Common Terminology Criteria for Adverse Events version 4.0. Comparison of characteristics and outcome was carried out with the Mann-Whitney test and analysis of overall survival with the log-rank test. RESULTS: In all, 129 patients were treated during the study period. Clinical benefit was similar in both groups. However, a statistically significant higher proportion of patients in the younger group had previously been treated with docetaxel. There was a higher rate of grade 3 anemia in younger patients. CONCLUSIONS: In line with other studies, 223Ra was well tolerated with minimum toxicities. The significantly higher rate of grade 3 anemia in younger patients may be due to more cautious patient selection in the elderly population.