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

Is there a role for neoadjuvant therapies followed by radical cystectomy in oligometastatic bladder cancer?

PURPOSE OF REVIEW

This review explores the potential role of neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) for oligometastatic bladder cancer (OMBC) treatment. We focused on extrapolating evidence from studies including lymph node-positive only and metastatic bladder cancer to address the key challenges and therapeutic strategies for OMBC.

RECENT FINDINGS

Current evidence for NAC and RC in OMBC is limited, with most data derived from studies in locally advanced bladder cancer. NAC has shown efficacy in downstaging and improving survival in patients with locally advanced disease, but its benefits in OMBC remain speculative. Additionally, diagnostic uncertainties, particularly regarding the inclusion of pelvic lymph nodes and the role of FDG-PET/CT, pose significant challenges to accurate staging and treatment decisions. Recent studies highlight the potential of metastasis-directed therapy, but uncertainties remain on patient selection and treatment protocols for OMBC.

SUMMARY

There is need for prospective studies to evaluate neoadjuvant systemic treatments and RC specifically in OMBC. Moreover, resolving current diagnostic challenges is crucial to avoid undertreatment due to inaccurate staging. Until more concrete evidence emerges, changes to standard treatment protocols should be approached with caution and offered only within trials.

Oligometastatic Urothelial Cancer and Stereotactic Body Radiotherapy: A Systematic Review and an Updated Insight of Current Evidence and Future Directions

BACKGROUND

Stereotactic body radiation therapy (SBRT) is the most commonly used metastasis-directed therapy (MDT) for oligometastatic urothelial carcinoma (omUC). Despite efforts in defining this disease entity, open questions remain concerning the role of MDT and the use of biomarkers, imaging, and its combination with systemic therapies. The aim of the present systematic review is to provide an updated overview of the current clinical evidence on SBRT for omUC in terms of survival and local control benefits. We also aim to provide updates on controversial areas and future directions in this emerging field.

METHODS

With a systematic approach, following PRISMA recommendations, we searched two databases to identify and select articles published up until March 2024 reporting the use of SBRT for omUC with or without concomitant systemic therapies. Prospective randomized or non-randomized studies as well as retrospective studies were included.

RESULTS

Eight studies were selected for data extraction and 293 omUC patients treated with SBRT were collectively analyzed. In metachronous omUC patients, SBRT delivered with ablative doses (BED10 ≥ 78 Gy) was associated with a 2-year overall survival (OS) rate of 50.7% (95% CI 35.1-64.4%). The use of sub-ablative SBRT doses (BED10 = 43.2 Gy) in combination with immunotherapy did not demonstrate significant clinical outcome improvement in two prospective studies. The overall tolerance was good, with only one study reporting toxicity of grade 3 in up to 18% of the patients treated with SBRT in combination with immunotherapy.

CONCLUSIONS

SBRT is an effective and widely available MDT option in omUC, although this is based on a limited number of studies. Despite the attempt to use SBRT as an immune response trigger in combination with immunotherapy, no significant improvement in survival outcomes has been observed. The integration of new systemic agents with MDT will likely define a new scenario for the treatment of omUC. The review protocol was registered in PROSPERO, ID: CRD42024522381.

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.

Avelumab maintenance therapy for node-positive muscle invasive bladder cancer: a report of two cases

Background

Muscle-invasive bladder cancer (MIBC) with nodal involvement is associated with poor prognosis and high mortality. Treatment of node-positive MIBC is complex due to disease heterogeneity and a lack of evidence-based treatment options, especially alternatives to radical cystectomy. We describe a bladder-sparing management approach involving systemic therapy followed by maintenance therapy, illustrated with two cases of node-positive MIBC.

Case presentation

Two patients with node-positive MIBC received upfront gemcitabine/cisplatin chemotherapy, concurrent chemoradiotherapy (cCRT), and avelumab (immune checkpoint inhibitor) maintenance therapy. Both patients achieved complete remission without recurrence or distant metastasis post-avelumab maintenance therapy. At the last follow-up, Patient 1 (45-year-old male) was in remission for over two years, and Patient 2 (57-year-old male) was in complete remission for over one year post-chemotherapy. Avelumab treatment was well-tolerated, with no immune-related adverse events, and quality of life (QoL) was maintained.

Conclusion

Both cases showed a good response and extended remission on avelumab maintenance, supporting its use in conjunction with local consolidation therapy as a bladder-preserving approach in node-positive MIBC. Further research, such as the ongoing INSPIRE trial, is required to refine treatment strategies for this patient group.

Management of Oligometastatic and Locally Recurrent Urothelial Carcinoma

PURPOSE OF REVIEW

To summarize and evaluate the literature on treatment approaches for oligometastatic and locally recurrent urothelial cancer.

RECENT FINDINGS

There is no clear definition for oligometastatic urothelial cancers due to limited data. Studies focusing on oligometastatic and locally recurrent urothelial cancer have been primarily retrospective. Treatment options include local therapy with surgery or radiation, and generalized systemic therapy such as chemotherapy or immunotherapy. Oligometastatic and locally recurrent urothelial cancers remain challenging to manage, and treatment requires an interdisciplinary approach. Systemic therapy is nearly always a component of current care in the form of chemotherapy, but the role of immunotherapy has not been explored. Consideration of surgical and radiation options may improve outcomes, and no studies have compared directly between the two localized treatment options. The development of new prognostic and predictive biomarkers may also enhance the treatment landscape in the future.

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.

Radiotherapy in metastatic bladder cancer

PURPOSE

To review available and emerging evidence of radiotherapy for symptom management and disease control in metastatic bladder cancer.

METHODS

A literature search and subsequent cross-referencing were carried out for articles in the PubMed and Scopus databases using terms 'radiotherapy' OR 'palliative radiation therapy' with 'metastatic bladder cancer' OR 'advanced bladder cancer' between 1990 and 2023, excluding articles with no English translation.

RESULTS

Palliative radiotherapy is an effective and accessible treatment for the alleviation of haematuria and pain due to the primary and metastatic disease. With growing recognition of oligometastatic disease state at diagnosis, response, or progression, radiotherapy can consolidate response by ablating residual or resistant lesions. Experience with other primary cancers supports positive impact of radiotherapy on disease control, quality of life, and survival in oligometastatic stage, without significant adverse effects. Alongside immune checkpoint inhibitors, fibroblast growth receptor inhibitors, and antibody-drug conjugates, the immunomodulatory potential of radiotherapy is being explored in combination with these systemic therapies for metastatic bladder cancer.

CONCLUSION

Radiotherapy is an effective, safe, and accessible treatment modality for palliation as well as disease control in various clinical settings of metastatic bladder cancer. Its role in oligometastatic stage in combination with systemic therapy is expected to expand with emerging evidence.

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.