# Incidence, Mortality and Survival Time Trends of Brain and CNS Tumours in the Canton of Zurich (Switzerland) Between 1980 and 2021

## TL;DR

This study examines how brain and CNS tumor rates and survival changed in Zurich from 1980 to 2021, finding rising benign tumor rates and improved survival.

## Contribution

The study provides detailed, localized trends in brain tumor incidence, mortality, and survival in Zurich over four decades.

## Key findings

- Benign/borderline tumor incidence increased significantly over time, especially in women.
- Malignant tumor incidence and mortality remained stable, while survival improved slightly.
- Improved survival for benign tumors may be due to better diagnostics and treatments.

## Abstract

We aimed to analyse trends in incidence, mortality and 5‐year relative survival of malignant and benign/borderline brain and central nervous system (CNS) tumours between 1980 and 2021 in the Canton of Zurich, Switzerland, stratified by sex, age group, behaviour and histological subtypes.

We used incidence data from the Cancer Registry of Zurich, Zug, Schaffhausen and Schwyz, including primary benign/borderline and malignant tumours diagnosed between 1980 and 2021 in the Canton of Zurich in patients aged ≥ 15 years (N = 10,226). Mortality data were provided by the Swiss Federal Statistical Office (N = 3514). We calculated age‐standardised incidence and mortality rates per 100,000 person‐years and used Joinpoint to analyse trends.

The age‐standardised incidence rate of malignant tumours was stable over time (around 7.7–8.2 per 100,000 person‐years in men and 4.6–5.2 in women), while the rate of benign/borderline tumours increased from 3.8 in 1980–1990 to 10.8 in 2011–2021 in men and from 5.7 to 19.1 in women. The age‐standardised mortality rate remained stable over time for malignant tumours (around 5.5–6.1 in men and 3.5–4.0 in women) but significantly decreased for benign/borderline tumours (from 1.0 to 0.5 in men and from 1.2 to 0.5 in women). Age‐standardised 5‐year relative survival increased from around 80% in 1980–1989 up to > 90% in 2011–2017 for benign/borderline tumours and from < 20% to around 30% for malignant tumours. There was a small survival advantage in women compared to men.

We observed an increase in incidence and a decrease in mortality rates for benign/borderline tumours, while both rates remained stable for malignant tumours. Five‐year relative survival improved over time. The increasing incidence rates in benign/borderline tumours may be due to improved diagnostic techniques and an increasing use of CT scans, as reported in other countries. The increase in relative survival may reflect earlier detection and better treatment options.