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.

Bladder-Sparing Treatment With Radical Dose Radiotherapy Is an Effective Alternative to Radical Cystectomy in Patients With Clinically Node-Positive Nonmetastatic Bladder Cancer.

PURPOSE: Bladder-sparing trimodal therapy (TMT) is an alternative to radical cystectomy (RC) according to international guidelines. However, there are limited data to guide management of nonmetastatic clinically node-positive bladder cancer (cN+ M0 BCa). We performed a multicenter retrospective analysis of survival outcomes in node-positive patients to inform practice. METHODS: Data from patients diagnosed with cN+ M0 BCa were collected from participating UK Oncology centers offering both TMT and RC. Overall survival (OS) and progression-free survival (PFS) outcomes were collected with details of treatment and clinical factors. RESULTS: A total of 287 patients with cN+ M0 BCa were included in the survival analysis. Median OS across all patients was 1.55 years (95% CI, 1.35 to 1.82 years). Receiving radical treatments was associated with improved OS (hazard ratio [HR], 0.32; 95% CI, 0.23 to 0.44; P < .001) compared with receiving palliative treatment. Radically treated patients (n = 163) received RC (n = 76) or radical dose radiotherapy (RT, n = 87); choice of radical treatment showed no association with OS (HR, 0.94; 95% CI, 0.63 to 1.41; P = .76) or PFS (HR, 0.74; 95% CI, 0.50 to 1.08; P = .12) on multivariable analysis. CONCLUSION: Patient cohorts with cN+ M0 BCa had equivalent survival outcomes whether treated with surgery or radical RT. Given the known morbidities of RC-in a patient group with poor survival-this study confirms that bladder-sparing TMT treatment should be a treatment option available to all patients with cN+ M0 BCa.

A Randomized, Double-Blind, Biomarker-Selected, Phase II Clinical Trial of Maintenance Poly ADP-Ribose Polymerase Inhibition With Rucaparib Following Chemotherapy for Metastatic Urothelial Carcinoma.

PURPOSE: A DNA repair deficiency (DRD) phenotype exists within a subset of metastatic urothelial carcinomas (mUC) predicting benefit from platinum-based chemotherapy. We tested switch maintenance therapy with the poly ADP-ribose polymerase inhibitor rucaparib, following chemotherapy, for DRD biomarker-positive mUC. METHODS: DRD biomarker-positive mUC patients, within 10 weeks of chemotherapy, and without cancer progression, were randomly assigned (1:1) to maintenance rucaparib 600 mg twice a day orally, or placebo, until disease progression. The primary end point was progression-free survival (PFS). Statistical analysis targeted a hazard ratio of 0.5 with a 20% one-sided α for this signal-seeking trial. PFS (RECIST 1.1) was compared between trial arms, by intention to treat, within a Cox model. RESULTS: Out of 248 patients, 74 (29.8%) were DRD biomarker-positive and 40 were randomly assigned. A total of 12 (60%) and 20 (100%) PFS events occurred in the rucaparib and placebo arms, respectively (median follow-up was 94.6 weeks in those still alive). Median PFS was 35.3 weeks (80% CI, 11.7 to 35.6) with rucaparib and 15.1 weeks (80% CI, 11.9 to 22.6) with placebo (hazard ratio, 0.53; 80% CI, 0.30 to 0.92; one-sided P = .07). In the safety population (n = 39) treatment-related adverse events were mostly low grade. Patients received a median duration of 10 rucaparib or six placebo cycles on treatment. Treatment-related adverse events (all grades) of fatigue (63.2% v 30.0%), nausea (36.8% v 5.0%), rash (21.1% v 0%), and raised alanine aminotransferase (57.9% v 10%) were more common with rucaparib. CONCLUSION: Maintenance rucaparib, following platinum-based chemotherapy, extended PFS in DRD biomarker-selected patients with mUC and was tolerable. Further investigation of poly ADP-ribose polymerase inhibition in selected patients with mUC is warranted.