# Trends in the incidence of brain cancer and the use of mobile phones: analysis of the Spanish Network of Cancer Registries (REDECAN)

## TL;DR

This study examines trends in brain cancer incidence in Spain from 1985 to 2015 and finds no evidence linking it to mobile phone use.

## Contribution

The study provides updated Spanish data on CNS cancer trends and evaluates their potential ecological correlation with mobile phone use.

## Key findings

- Adult brain cancer rates increased slightly until 1996 then declined, while children's rates rose until 1991 then fell.
- The observed incidence changes are likely due to improved diagnostics rather than mobile phone use.
- No significant correlation was found between mobile phone use and brain cancer incidence.

## Abstract

The association between the use of mobile phones use and the risk of brain cancer remains controversial. The aim of this study is to describe trends in the incidence of central nervous system (CNS) cancers in Spain and its possible relationship with mobile phone use.

Trends and trend changes from 1985 to 2015 in adjusted incidence rates of CNS cancers by sex, age (adults and children), site, and histological type were assessed using data from 14 general and paediatric cancer registries.

The study included 20,325 CNS malignancies in adults and 2,372 in children. For adults, the overall rate of malignant brain tumours showed a slight increase of 0.2% (95% CI: 0.1 - 0.4) per year. This increase was concentrated in the early years up to 1996 (1.7% per year, 95% CI: 0.9 - 2.6) followed by 20 years of a non-significant slight decline of -0.1% (95% CI: -0.4 - 0.1) per year until 2015. In children, an increase of 7.6% (95% CI: 2.4 – 13.1) per year until 1991 followed by a decrease of -1.0% (95%CI: -1.7 - -0.3) per year until 2015 was observed. This increase in the incidence in 1980s and early 1990s could be explained by diagnostic improvements especially in imaging techniques implemented during these years.

The present findings do not support a possible relationship between the use of mobile phones and the incidence of malignant brain tumours. However, the possibility of the presence of a weak correlation or that a longer latency period would be needed to observe a possible ecological correlation cannot be discarded.

The online version contains supplementary material available at 10.1007/s12094-025-03932-y.