Metastasis-Directed Radiation Therapy with Consolidative Intent for Oligometastatic Urothelial Carcinoma: A Systematic Review and Meta-Analysis

Radiotherapy plus pembrolizumab for advanced urothelial carcinoma: results from the ARON-2 real-world study

The addition of metastasis-directed radiotherapy (MDRT) to immunotherapy in patients with advanced urothelial carcinoma (aUC) has shown promising results. We report the real-world data from the ARON-2 study (NCT05290038) on the impact of conventional (CRT) or stereotactic body radiotherapy (SBRT) on the outcome of aUC patients receiving pembrolizumab after platinum-based-chemotherapy. Medical records of 837 patients were reviewed from 60 institutions in 20 countries. Two hundred and sixty-two patients (31%) received radiotherapy (cohort A), of whom 193 (23%) received CRT and 69 (8%) received SBRT. Patients were assessed for overall survival (OS), progression-free survival (PFS), and overall response rate (ORR). Univariate and multivariate analyses were used to explore the association of variables of interest with OS and PFS. With a median follow-up of 22.7 months, the median OS was 10.2 months, 6.8 months and 16.0 months in no RT, CRT and SBRT subgroups (p = 0.005), with an 1y-OS rates of 47%, 34% and 61%, respectively (p < 0.001). The 1y-OS rate in the SBRT subgroup were significantly higher for both lower (63%) and upper tract UC (68%), for pure urothelial histology (63%) and variant histologies (58%), and for patients with bone (40%) and lymph-node metastases (61%). Median PFS was 4.8 months, 9.6 months and 5.8 months in the CRT, SBRT and no RT subgroups, respectively (p = 0.060). The 1y-PFS rate was significantly higher (48%) in the SBRT population and was confirmed in all patient subsets. The difference in terms of ORR was in favour of SBRT. Our real-world analysis showed that the use of SBRT/pembrolizumab combination may play a role in a subset of aUC patients to increase disease control and possibly overall survival.

Is there a role for metastasis-directed therapy in bladder cancer?

PURPOSE OF REVIEW

This article aims to comprehensively review and critique the existing literature on the role of metastatic-directed therapy in patients with metastatic bladder cancer, particularly in oligometastatic disease state.

RECENT FINDINGS

The role of metastasectomy in metastatic bladder cancer is still controversial. Several studies have demonstrated improved outcomes, particularly in a highly selected patients with small metastatic lesions or with lung or brain metastases, whereas others show no significant survival benefit. Combining metastasectomy with systemic therapies, such as immunotherapy and chemotherapy, has also shown benefits. Metastasis-directed radiotherapy is evolving as a potentially effective approach with minimal toxicity in achieving local control and improving survival, particularly in patients with oligometastatic disease. The evidence regarding the impact of several factors such as performance status, metastatic burden, and the presence of visceral metastases on outcomes is mixed. Concurrent treatment with systemic therapy may potentiate the effectiveness of metastasis-directed therapy.

SUMMARY

In patients with metastatic deposits amenable to surgical resection, metastasectomy stands as a promising avenue. Metastatic-directed radiotherapy has demonstrated local control and improved survival in the evolving landscape of oligometastatic bladder cancer management. Further, well designed multicenter prospective studies are needed to support these findings and better understand the synergy between radiotherapy and systemic treatments, especially immunotherapy.

Stereotactic body radiation therapy is beneficial for a subgroup of patients with urothelial cancer and solitary metastatic disease: a single institution real-world experience

BACKGROUND

Standard treatment options for patients with metastatic urothelial cancer (mUC) include systemic platinum-based chemotherapy, immunotherapy, antibody-drug-conjugates, and targeted therapy. Oligometastatic disease (OMD) may be an intermediate state between localized and generalized cancer. The best treatment strategy for OMD and oligoprogressive (OPD) disease is poorly studied in mUC but local stereotactic body radiation therapy (SBRT) could be an option to avoid or delay systemic treatment. The aim of this study was to assess the efficacy and feasibility of SBRT given in a real-world patient population.

METHODS

All patients with mUC treated with SBRT at Karolinska University Hospital, Stockholm, Sweden between 2009 and 2022 were included in this study. Baseline clinical characteristics, treatment data, SBRT dosimetry data and treatment outcome were collected retrospectively. The study endpoints were local control rate (LCR), progression-free-survival (PFS), overall survival (OS) and feasibility of SBRT.

RESULTS

In total 39 patients were treated with SBRT. The median follow-up was 25.6 months. The LCR was 82%. PFS and OS were 4.1 and 26.2 months, respectively. Treatment was well tolerated; all patients but one (treatment related pain) completed the planned SBRT. Number of metastases irradiated with SBRT was significantly associated with outcome; patients with only one irradiated lesion had more favourable PFS compared to individuals with 2 or more metastases (HR 4.12, 95% CI: 1.81-9.38, p = 0.001). A subgroup of patients (15%) achieved a sustained long-term survival benefit and never required systemic treatments after SBRT.

CONCLUSIONS

SBRT was well tolerated and associated with high LCR. A subpopulation of patients with single metastatic lesion achieved long-term OS and never required subsequent systemic treatment after SBRT. Prospective randomized studies are warranted to discover treatment predictive biomarkers and to investigate the role of SBRT in oligometastatic UC.

Muscle-invasive bladder cancer in elderly and frail people: Is hypofractionated radiotherapy a feasible approach when no other local options are available?

AIM

The study aims to report the feasibility and safety of palliative hypofractionated radiotherapy targeting macroscopic bladder tumors in a monocentric cohort of frail and elderly bladder cancer patients not eligible for curative treatments.

METHODS

Patients who underwent hypofractionated radiotherapy to the gross disease or to the tumor bed after transurethral resection of bladder tumor from 2017 to 2021 at the European Institute of Oncology IRCCS, were retrospectively considered. Schedules of treatment were 30 and 25 Gy in 5 fractions (both every other day, and consecutive days). Treatment response was evaluated with radiological investigation and/or cystoscopy. Toxicity assessment was carried out according to RTOG/EORTC v2.0 criteria.

RESULTS

A total of 16 patients were included in the study, of these 11 received hypofractionated radiotherapy on the macroscopic target volume and five on the tumor bed after transurethral resection of bladder tumor. No grade (G) >2 acute toxicities were described after treatment for both groups. Only one patient in the group receiving radiotherapy on the macroscopic disease reported G4 GU late toxicity. Ten patients had available follow-up status (median FU time 18 months), of them six had complete response, one had stable disease, and three had progression of disease. The overall response rate and disease control rate were 60% and 70%, respectively.

CONCLUSION

Our preliminary data demonstrate that palliative hypofractionated radiotherapy for bladder cancer in a frail and elderly population is technically feasible, with an acceptable toxicity profile. These outcomes emphasize the potential of this approach in a non-radical setting and could help to provide more solid indications in this underrepresented setting of patients.

Definitions, outcomes and perspectives for oligometastatic bladder cancer: towards a standardized terminology

PURPOSE OF REVIEW

Oligometastatic (om) cancer is considered as a transitional state in between locally confined disease and widespread metastases, accessible to a multimodal treatment, combining systemic and local therapy. In urothelial bladder cancer (BCa), the definitions and the approaches to this condition are poorly standardised and mainly based on retrospective data. We aim to portray the framework for uro-oncologic terminology in omBCa and go through the latest evidence and the future perspectives.

RECENT FINDINGS

Retrospective and registry data support the potential benefits of multimodality treatment for carefully selected omBCa patients, especially following a good response to systemic treatment. In 2023, a Delphi consensus has defined omBCa, allowing maximum three metastatic lesions, theoretically amenable to radical local treatment. In de-novo omBCa, surgical treatment of primary tumour might improve overall survival (OS), according to a matched registry analysis; also, consolidative radiotherapy was associated with better OS in two recent cohorts. Furthermore, metastasis-directed therapy (MDT) has shown high local control rates and promising OS (14.9-51 months) in a meta-analysis; benefits might be more pronounced for single-site omBCa and nodal or lung lesions.

SUMMARY

From a clinical perspective, in de-novo omBCa, the local treatment of primary and metastatic sites might improve disease control and survival, in selected patients; in the oligorecurrent setting, MDT achieves good local symptom control with limited side effects; in selected cases, it could convey a survival benefit, too. From a research perspective, well designed prospective evidence is eagerly awaited, based on recently adopted shared definitions for omBCa.

Occult urothelial carcinoma with mediastinal metastasis: A case report

Occult urothelial carcinoma (UC), particularly with mediastinal metastases, is an uncommon clinical occurrence. The present study describes the unusual case of a 70-year-old male patient who developed mediastinal metastases from an occult UC. Histological evaluations and immunohistochemical features of the mediastinal tumor were indicative of UC; however, extensive imaging failed to identify the primary urological lesion. The findings suggest that mediastinal metastases from UCs, despite their rarity, should be considered in cases where patients with mediastinal tumors exhibit chest-related symptoms. Prompt pathological examinations are crucial for ascertaining the nature and origin of the tumor. Moreover, individualized treatment should be performed in strict accordance with the established oncology guidelines.

Identification of Molecular Mechanisms in Radiation Cystitis: Insights from RNA Sequencing

Pelvic cancer survivors who were treated with radiation therapy are at risk for developing (hemorrhagic) radiation cystitis (RC) many years after completion of radiation therapy. Patients with RC suffer from lower urinary tract symptoms, including frequency, nocturia, pelvic pain, and incontinence. In advanced stages, hematuria can occur, potentially escalating to life-threatening levels. Current therapeutic options for RC are limited, partly due to ethical concerns regarding bladder biopsy in patients with fragile bladder tissue. This study aimed to leverage our established preclinical model to elucidate the molecular pathways implicated in radiation-induced tissue changes in the bladder. Female C57Bl/6 mice received a single dose of 40 Gy using CT-guided imaging and a two-beam irradiation approach using the SARRP irradiator. Bladders from irradiated and age-matched littermate controls were harvested at 1 week [n = 5/group] or 6 months [n = 5/group] after irradiation, RNA was harvested, and mRNA sequencing was performed at paired-end 150bp on the Illumina NovaSeq6000 with a target of 30 million reads per sample. Following RNA sequencing, thorough bioinformatics analysis was performed using iPathwayGuide v2012 (ADVAITA Bioinformatics). Findings of the RNA sequencing were validated using qPCR analysis. At 1 week post-irradiation, altered gene expression was detected in genes involved in DNA damage response, apoptosis, and transcriptional regulation. By 6 months post-irradiation, significant changes in gene expression were observed in inflammation, collagen catabolism, and vascular health. Affected pathways included the p53, JAK-STAT, and PI3K-Akt pathways. These findings were validated in vivo in bladder tissues from our preclinical model. This is the first study to determine the molecular changes in the bladder in response to radiation treatment. We have successfully pinpointed several pathways and specific genes that undergo modification, thereby contributing to the progression of radiation cystitis. These insights enhance our understanding of the pathophysiology of radiation cystitis and may ultimately pave the way to the identification of potential new therapeutic targets.

A Real-World Retrospective Analysis of the Management of Advanced Urothelial Carcinoma in Canada

Locally advanced or metastatic urothelial carcinoma (aUC) presents a significant challenge with high mortality rates. Platinum-based chemotherapy remains the established frontline standard of care, and a switch-maintenance strategy with immunotherapy has now emerged as a new standard for aUC patients without disease progression, following initial platinum therapy. Examining the treatment patterns is imperative, given the evolving therapeutic landscape. In this study, we conducted a retrospective medical chart review of 17 Canadian oncologists treating patients with aUC to assess unmet needs in Canadian aUC patient care. Data from 146 patient charts were analyzed, revealing important clinical insights about the management of aUC. A substantial proportion of patients (53%) presented with de novo metastatic disease, which was possibly influenced by pandemic-related care disruptions. Variability was evident in the cisplatin eligibility criteria, with a majority (70%) of oncologists utilizing a 50 mL/min threshold. Most favored four cycles of platinum-based chemotherapy to spare the bone marrow for future therapies and prevent patient fatigue. Notably, some eligible patients were kept under surveillance rather than receiving maintenance therapy, suggesting a potential gap in awareness regarding evidence-based recommendations. Furthermore, managing treatment-related adverse events was found to be one of the biggest challenges in relation to maintenance immunotherapy. In conclusion, our findings provide the first comprehensive overview of aUC treatment patterns in Canada following the approval of maintenance immunotherapy, offering insights into the decision-making process and underscoring the importance of evidence-based guidelines in aUC patient management.

Navigating the Rapidly Evolving Advanced Urothelial Carcinoma Treatment Landscape: Insights from Italian Experts

PURPOSE OF REVIEW

To discuss recent advances in the treatment of advanced urothelial carcinoma (UC) and how best to incorporate new therapies into clinical practice.

RECENT FINDINGS

There have been several recent practice-changing phase 2 and 3 trials of immune checkpoint inhibitors (ICIs), antibody-drug conjugates (ADCs), and targeted agents in advanced UC. Based on data from these trials, ICIs can be used as first-line maintenance therapy in patients who do not progress on platinum-based chemotherapy, second-line therapy for those with progression, and first-line therapy in cisplatin-ineligible patients with PD-L1 expression; ADCs and targeted agents provide later-line treatment options. Despite substantial progress in the treatment of advanced UC, there are still many uncertainties, including the optimal treatment sequence for novel agents, and reliable predictive biomarkers to aid in treatment selection. There is also an unmet need for effective treatment options in patients unfit for any platinum-based chemotherapy.

Defining Oligometastatic Bladder Cancer: A Systematic Review

Context

Unlike other cancers, the concept of oligometastatic disease (OMD) in bladder cancer (BC) has not been systematically investigated. There is therefore a need to develop universally accepted definitions and guidelines for the management of oligometastatic BC (OMBC).

Objective

To conduct a systematic review to assist a European consensus group in producing a definition of OMBC and to provide recommendations on staging and local therapies.

Evidence acquisition

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was followed. Abstracts for articles focused on BC that addressed the issue of OMBC and provided a definition of oligometastatic status were selected. We collected data on the number of metastases, the number of metastases per organ, the number of organs involved, and metastatic sites that were excluded.

Evidence synthesis

Sixteen eligible articles were retrieved (9 retrospective series involving 330 patients, 4 reviews, 1 consensus statement, 1 guideline paper, and 1 ongoing prospective phase 2 trial). A maximum of three to five metastatic lesions were compatible with the definition of OMBC. The number of organs involved and lesion size were not universally included in the OMBC definitions. OMD categories studied included synchronous OMBC, oligorecurrence, and oligoprogression. 18F-Fluorodeoxyglucose positron emission tomography combined with computed tomography was used in addition to conventional imaging for OMD detection. Surgery and radiotherapy were both used. Systemic chemotherapy was also used in all studies.

Conclusions

There is little information on OMBC in the literature. Our systematic review revealed that only three to five metastatic sites amenable to surgery or radiotherapy that respond to systemic therapy is the setting most frequently chosen for a combination of systemic treatment and metastases-directed therapy. This setting could represent a basis for future prospective studies on OMBC.

Patient summary

Oligometastatic bladder cancer is a disease state in which favorable outcomes can be expected after a treatment combination of systemic therapy, plus surgery and/or radiotherapy for sites of bladder cancer metastasis. Our systematic review showed a lack of meaningful evidence to define this disease state. There is an urgent need to develop organized research in this field.

Radiotherapy Use in Muscle-Invasive Bladder Cancer: Review of the Guidelines and Impact of Increased Awareness in Patient Referral at a Tertiary Center in Belgium

Purpose

Pronounced underuse of radiotherapy (RT) in muscle-invasive bladder cancer (MIBC) is reported. This study aims to assess the awareness about the role of RT in different MIBC settings and see whether this has increased since 2017.

Materials and Methods

We reviewed the bladder cancer guidelines of the EAU, ESMO, NCCN, NICE, and AUA/ASCO/ASTRO/SUO, focusing on the role of RT in MIBC. In 2017, we evaluated the use of RT in MIBC in Belgium. This raised awareness about the indications of RT in different MIBC settings. Here, we present a retrospective pattern of care analysis of the RT use for MIBC patients at our center from January 2012 until December 2021. Frequency of RT use, patient, disease and treatment characteristics were compared between two 5-year periods (2012-2016 and 2017-2021).

Results

Review of the guidelines suggested that RT can be used as a treatment option in most MIBC settings. However, differences between guideline recommendations existed and high-level evidence was often lacking. Overall, 221 unique MIBC patients received RT at our center. RT use for MIBC was 39% higher in the second 5-year period (Between the same periods, the number of new MIBC registrations increased with 26%). The most pronounced increase, ie, 529%, was observed in the primary setting and was in parallel with patient preference becoming the main indication for RT. Participation in clinical trials seems to have had an important impact on the frequency of RT use in the adjuvant and metastatic setting.

Conclusion

We provide a critical overview of the RT indications in MIBC as recommended by the international guidelines. Increased awareness about RT as a treatment option in MIBC seems to have an impact on the treatment choice in clinical practice, as was observed in our tertiary center.

Clinical application and efficacy analysis of partial cystectomy combined with intravesical chemotherapy in muscle-invasive bladder cancer

OBJECTIVES

Comparing the long-term tumor control results of partial cystectomy(PC)and radical cystectomy(RC)in the treatment of muscle-invasive bladder cancer, and to explore the feasible method of bladder preservation therapy (BPT)in patients with MIBC.

METHODS

We retrospectively analyzed the clinical data of 102 patients with muscle-invasive bladder cancer in our hospital between January 2012 and December 2018, of whom 32 cases in the partial cystectomy group and 70 cases in the radical cystectomy group. We performed a comparative analysis of patient general information, perioperative-related indicators and postoperative follow-up data, comparing OS, PFS, and DSS at 1, 2, 3, 4, and 5 years in both groups, and comparing tumour recurrence and metastasis in postoperative patients.

RESULTS

All the 102 cases in this study were successfully completed. Partial cystectomy group and Radical cystectomy group median operating time (169.50(130.00 ~ 225.25) min and 420.00(343.75 ~ 483.75) min, p < 0.001), median intraoperative blood loss was (100(50 ~ 100)ml and 400(200 ~ 1000)ml, p < 0.001), median perioperative blood transfusion volume (0(0 ~ 0)ml and 600(150.00 ~ 906.25)ml, p < 0.001), median total hospital stay (18(14.25 ~ 20.00) and 24.5(20.00 ~ 34.25) days, p < 0.001), median preoperative preparation time (7(4.25 ~ 8.00) and 10(8.00 ~ 13.00) days, p < 0.001), median postoperative hospital stay (9(8.00 ~ 13.50) and 14(11.00 ~ 21.25) days, p < 0.001), the incidence of perioperative blood transfusion was (15.6% and 75.7%, p < 0.001), the incidence of surgical complications was(28.1%(9/32) and 50.0%(35/70), p = 0.033), average hospitalization cost ((26435.76 ± 9877.82) yuan and (58464.36 ± 19753.13) yuan, p < 0.001), the differences were statistically significant (p < 0.05). Perioperative mortality (0 vs. 2.9%(2/70), p = 1), and OS at 1, 2, 3, 4, and 5 years after surgery were (80.0%, 59.8%, 56.1%, 51.0%, 44.6% vs. 76.5%, 67.4%, 64.9%, 57.9%, 52.6%, p = 0.524), PFS (68.2%, 64.6%, 60.3%, 54.8%, 54.8% vs. 82.7%, 78.3%, 75.4%, 67.3%, 62.1%, p = 0.259). DSS (89.9%, 72.4%, 68.6%, 68.6%, 62.4% vs. 87.3%, 83.4%, 80.9%, 73.6%, 68.0%, p = 0.424), and the incidence of tumor recurrence or metastasis was (40.0%(12/30) vs. 25.4%(16/63), p = 0.151), the differences were not statistically significant (p > 0.05).

CONCLUSION

In patients with limited solitary T2N0M0 and T3N0M0 muscle-invasive bladder cancer, partial cystectomy plus bladder instillations treatment can achieve comparable tumour control to radical cystectomy. However, patients in the PC group have significant advantages in terms of operative time, intraoperative bleeding, intraoperative and postoperative blood transfusion, preoperative preparation time, total hospital stay, postoperative recovery time, operative costs and operative complications. This option may be considered for such patients with a need for bladder preservation.

Consolidative Radiotherapy for Metastatic Urothelial Bladder Cancer Patients with No Progression and with No More than Five Residual Metastatic Lesions Following First-Line Systemic Therapy: A Retrospective Analysis

Local consolidative radiotherapy in the treatment of metastatic malignancies has shown promising results in several types of tumors. The objective of this study was to assess consolidative radiotherapy to the bladder and to residual metastases in metastatic urothelial bladder cancer with no progression following first-line systemic therapy.

MATERIALS/METHODS

Patients who received first-line therapy for the treatment of metastatic urothelial bladder cancer (mUBC) and who were progression-free following treatment with no more than five residual metastases were retrospectively identified through the database of four Comprehensive Cancer Centers, between January 2005 and December 2018. Among them, patients who received subsequent definitive radiotherapy (of EQD2Gy > 45Gy) to the bladder and residual metastases were included in the consolidative group (irradiated (IR) group), and the other patients were included in the observation group (NIR group). Progression-free survival (PFS) and overall survival (OS) were determined from the start of the first-line chemotherapy using the Kaplan-Meier method. To prevent immortal time bias, a Cox model with time-dependent covariates and 6-month landmark analyses were performed to examine OS and PFS.

RESULTS

A total of 91 patients with at least stable disease following first-line therapy and with no more than five residual metastases were analyzed: 51 in the IR group and 40 in the NIR group. Metachronous metastatic disease was more frequent in the NIR group (19% vs. 5%, p = 0.02); the median number of metastases in the IR group vs. in the NIR group was 2 (1-9) vs. 3 (1-5) (p = 0.04) at metastatic presentation, and 1 (0-5) vs. 2 (0-5) (p = 0.18) after completion of chemotherapy (residual lesions), respectively. Two grade 3 toxicities (3.9%) and no grade 4 toxicity were reported in the IR group related to radiotherapy. With a median follow up of 85.9 months (95% IC (36.7; 101.6)), median OS and PFS were 21.7 months (95% IC (17.1; 29.7)) and 11.1 months (95% IC (9.9; 14.1)) for the whole cohort, respectively. In multivariable analysis, consolidative radiotherapy conferred a benefit in both PFS (HR = 0.49, p = 0.007) and OS (HR = 0.47, p = 0.015) in the whole population; in the landmark analysis at 6 months, radiotherapy was associated with improved OS (HR = 0.48, p = 0.026), with a trend for PFS (HR = 0.57, p = 0.082).

CONCLUSION

Consolidative radiotherapy for mUBC patients who have not progressed after first-line therapy and with limited residual disease seems to confer both OS and PFS benefits. The role of consolidative radiotherapy in the context of avelumab maintenance should be addressed prospectively.

Optimal Systemic Treatment of Advanced Bladder Cancer Calls for a Multidisciplinary Approach

Although the bladder cancer treatment field is expanding with several new treatments introduced in the last decade, many patients with an advanced form of the disease can expect a poor prognosis when diagnosed [...].