# Current surveillance in the Netherlands for urothelial carcinoma in lynch syndrome

## TL;DR

This study examines current urothelial carcinoma surveillance practices in Lynch syndrome patients in the Netherlands and finds that surveillance does not lead to early detection.

## Contribution

The study provides real-world data on UC surveillance effectiveness in Lynch syndrome, highlighting the lack of benefit from current strategies.

## Key findings

- 40% of individuals with Lynch syndrome underwent UC surveillance, but none of the tests led to a UC diagnosis.
- Cumulative UC incidence was 9% at age 75, but most individuals were not part of a surveillance program.
- Two UC cases were diagnosed due to symptoms, not through surveillance tests.

## Abstract

Lynch syndrome (LS) is a hereditary cancer predisposition syndrome caused by a pathogenic germline variant in one of the mismatch repair (MMR) genes. There is a lack of evidence supporting surveillance for urothelial carcinoma (UC) in LS, however several surveillance strategies have been proposed in recent years. This has led to a variety of practices. This study reports on the current practice for UC surveillance in LS in the Netherlands. Individuals with LS from two university hospitals and a large comprehensive cancer center were selected. Data on UC surveillance and UC diagnoses were recorded. Cumulative incidence was calculated. Of 235 individuals with LS, 40% underwent UC surveillance. Individuals with a pathogenic MSH2 variant were under surveillance significantly more often than those with other pathogenic variants. Of the individuals who underwent surveillance 10% had annual testing and continued surveillance up until the last known follow up date. None of the surveillance tests led to a UC diagnosis. Of eight patients with UC, two were under active surveillance, but were diagnosed due to macroscopic hematuria after normal cytology results. Cumulative UC incidence was 9% at age 75. Currently, most individuals with LS in this cohort are not part of a surveillance program for UC. Cumulative UC risk is high, up to 9%, and none of the UC were detected by surveillance. Given the lack of evidence that a suitable surveillance test is available, we do not recommend surveillance for UC.