Malignant Ureteric Obstruction in Prostate Cancer: a National Population-based Study

Background Prostate cancer (PCa) is the most common cancer in men and the second most common cause of cancer-related death in the UK. 50% of patients with prostate cancer present with locally advanced or metastatic disease.

A complication of locally advanced and metastatic PCa is malignant ureteric obstruction (MUO) of the kidneys, which may cause kidney damage and death. MUO can be treated via percutaneous nephrostomy or ureteric stenting. However, little is known about MUO in PCa. The largest systematic review to date only identified 200 patients across seven studies who were treated for their MUO.

Therefore, many questions remain as to the patients at highest risk of MUO, the best treatments to prevent the development of MUO, the best treatment of MUO, the adverse consequences of treatment and the impact of treatment on survival.

Project Aim I aim to use national registry and hospital episode statistics data, linked at patient-level to investigate the risk factors for, management of, and implications of MUO in patients with locally advanced and metastatic prostate cancer.

Research Questions (RQ) 1: What factors put patients with prostate cancer at greater risk of developing malignant ureteric obstruction? 2: Does radically treating locally advanced and metastatic prostate cancer reduce the risk of developing malignant ureteric obstruction? 3: What are the adverse consequences of procedures used to treat patients with malignant ureteric obstruction secondary to prostate cancer? 4: How long can patients with malignant ureteric obstruction secondary to prostate cancer expect to survive?

Methods I will use de-identified patient-level population data consisting of multiple national registry databases and hospital episode statistics.

I have conducted preliminary work to develop a coding framework to identify the largest known cohort of 10,000 patients with an obstruction of their urinary tract with 2,000 of those undergoing a treatment for MUO.

Multivariable regression analysis will be used to identify risk factors of developing MUO (RQ 1) and the impact of primary PCa treatment on developing MUO (RQ 2). Comparative analyses and Cox-regression analyses will be used to compare treatment for MUO (RQ 3) and survival (RQ 4). Timeline This is a three-year project starting in October 2024.

I expect each research question to be addressed by RQ 1: March 2025 RQ 2: September 2025 RQ 3: March 2026 RQ 4: September 2026 Impact and Dissemination My work is patient-centric and aims to empower patients to make informed decisions, whilst educating clinicians on the best practice and advising healthcare systems on the best way to allocate resources.

Via patient information leaflets I will advise patients on the consequences of treatment of MUO, they will be informed as to the number of repeat procedures, complications, days spent in hospital and whether they can expect to live longer with treatment.

Via research publications and conference presentations I will advise urologists, oncologists, interventional radiology doctors and healthcare systems as to which patients are most at risk of developing MUO, which patients would benefit the most from treatment and what the best type of treatment is.