# Histotype-specific incidence and survival of urothelial carcinoma—an analysis of the German North Rhine-Westphalia Cancer Registry

## TL;DR

This study analyzed urothelial and non-urothelial urinary tract cancers in Germany, finding significant differences in survival rates based on tumor type and stage.

## Contribution

The study provides a detailed analysis of incidence and survival trends for specific histological subtypes of urinary tract cancers in a large population.

## Key findings

- Papillary invasive UC (PIUC) had the best survival rate at 72.0%, while OSTT had the worst at 23.8%.
- Survival rates dropped significantly with advancing tumor stages, especially for UC, PIUC, ADC, and UTT.
- The incidence of PIUC and UTT decreased over time, while OSTT incidence increased.

## Abstract

The aim of this study was to evaluate the incidence and survival of urothelial carcinoma (UC) and non-urothelial tumor types. The primary objective was to define the incidence and survival of pure UC and non-UC tumor types.

Malignant invasive urinary cancers of the urothelial tract diagnosed between 2008 and 2022 were identified via the North Rhine-Westphalia Cancer Registry and classified according to the 2016 World Health Organization (WHO) classification (fourth edition). Evaluation focused on pure tumor types: UC, papillary invasive UC (PIUC), squamous-cell carcinoma (SCC), adenocarcinoma (ADC), rarer tumor types and mixed histologies grouped under other specific tumor types (OSTT), and unspecified tumor types (UTT). The primary outcomes were age-standardized incidence rate with estimated annual percentage changes, and relative survival.

UC and PIUC were the most common histology types, accounting for 57.9% and 26.2% (n = 73 751), respectively. The age-standardized incidence of PIUC and UTT decreased over time in both sexes, while OSTT incidence increased over time. Incidence rate declined among men with SCC and among women with ADC. Relative survival was notably poor for SCC (32.3%) and OSTT (23.8%), in contrast to a more favorable outcome for PIUC (72.0%). Decreasing survival with advancing T-stages was noted, particularly for UC, PIUC, ADC, and UTT; T1 in PIUC showed the best survival (81.0%) and T3-4 in OSTT had the poorest survival (16.4%).

Relative survival was most favorable for PIUC, UC, and ADC. In contrast, SSC and OSTT exhibited poorer survival outcomes, highlighting a pressing medical need for enhanced treatment options for these subgroups.

•Relative survival highly varied by histology.•Worst survival was observed in OSTT.•Best survival was observed in PIUC.•Tumor stage strongly influenced survival, dropping from 76.1% (T1) to 33.7% (T3-4).

Relative survival highly varied by histology.

Worst survival was observed in OSTT.

Best survival was observed in PIUC.

Tumor stage strongly influenced survival, dropping from 76.1% (T1) to 33.7% (T3-4).