# The Impact of the Localization of Metastasis in Bladder Cancer Patients with Recurrence After Cystectomy

## TL;DR

This study shows that bladder cancer patients with metastases in specific locations, like bones or multiple organs, have worse survival outcomes compared to those with lymph node metastases.

## Contribution

The study provides new insights into how the anatomical location of metastases affects prognosis in bladder cancer patients after cystectomy.

## Key findings

- Bone and organ metastases are associated with worse prognosis than lymph node metastases.
- Patients with multiple metastatic sites have higher mortality risk than those with single-site recurrence.
- Survival probabilities differ significantly based on metastasis location in bladder cancer patients.

## Abstract

This study investigates the impact of the localization of metastasis in patients with bladder cancer that were treated with cystectomy. Not many studies have investigated this subject before in this patient group. We used a clinical quality database for this study. This study’s findings indicate that patients with bone metastases have worse prognosis than patients with lymph node metastases. The study’s finding also indicate that patients with organ metastases had worse prognosis than patients with lymph node metastases or local recurrence. Furthermore, we found that patients with multiple metastases have worse prognosis compared to patients with single recurrence.

Background/Objectives: The aim of this study is to assess the prognostic implications of metastatic anatomical location in patients with recurrent bladder cancer (BC) after cystectomy. Methods: The study is a retrospective cohort study. All data were collected from a clinical database from Aarhus University Hospital. Kaplan–Meier curves were used to analyse survival probabilities. Crude and adjusted Cox regression was used to calculate the hazard ratios (HRs) for overall mortality between different locations of metastases and the number of metastases. Results: In total, 180/664 (27.1%) patients who underwent radical cystectomy as a treatment of BC in the time period from 2015 to 2021 ultimately developed recurrent disease. The median follow-up period was 433 days (Q1: 256, Q3; 847). In a crude analysis for overall mortality, patients with both lymph node and distant organ metastasis had a worse prognosis than patients with lymph node metastasis only (HR = 2.25 (95% CI: 1.36–3.75, p = 0.002)). In the adjusted analysis, patients with ≥2 metastatic sites had higher hazard than patients with only a single site of recurrence (HR = 1.63 (95% CI: 1.15–2.33, p = 0.01)). Patients with organ metastasis had higher hazard ratios than patients with lymph node metastases and local recurrence only (HR = 1.74 (95% CI: 1.07–2.84, p = 0.026)). When analysing patients with single metastasis, there was a statistically significant difference in overall survival probability in the following groups: lymph node metastasis, other organ metastases, bone metastasis (p = 0.04). Conclusions: This study shows potentially clinically relevant associations between the anatomical location of metastases and patients’ prognosis. Furthermore, we were able to demonstrate an association between a higher number of metastatic sites and a worse prognosis.