Patients with Metastatic or Locally Advanced Bladder Cancer Not Undergoing Systemic Oncological Treatment-Characteristics and Long-Term Outcome in a Single-Center Danish Cohort.

BACKGROUND

A subset of patients with locally advanced or metastatic bladder cancer (la/mBC) do not receive systemic oncological treatment. The reasons for refraining from systemic treatment are poorly investigated, as are the characteristics of patients who turn out to be long-term survivors despite lack of treatment.

METHODS

This retrospective observational cohort study included patients with registration compatible with la/mBC who did not undergo systemic treatment. They were seen at a single tertiary university hospital covering one of 5 Danish regions in the study period from 1 January 2012 until 31 December 2022. Patients were identified through a coding system, and detailed patient information was obtained in the electronic medical records.

RESULTS

The initial study population consisted of 472 patients registered with la/mBC according to codes in the patient registries but with no registration of systemic oncological treatment. Out of the total cohort, 159 patients were registered correctly, while the rest of the population were excluded due to misclassification, as 10.8% did not have la/mBC and 55.5% had received oncological treatment. Among correctly registered patients, the median overall survival was 2.6 months (95% CI 0.26; 4.94) from being diagnosed with la/mBC. The most common reasons for lack of treatment were poor general condition (74.2%), patient preference (19.5%), and poor renal function (11.9%).

CONCLUSIONS

Our study found that a significant amount of patients in a cohort of suspected la/mBC not undergoing treatment either received oncological treatment or did not have la/mBC, demonstrating a misclassification in the system. This should be taken into consideration when evaluating data about survival time for this patient group. The poorest survival of untreated la/mBC is associated with a high tumor burden and specifically liver metastasis.