# Smoking and the occurrence of larynx cancer in Sweden – a population analysis

## TL;DR

This study examines how smoking habits in Sweden influenced larynx cancer rates in men and women from 1970 to 2021.

## Contribution

The study highlights that factors beyond cigarette smoking, like pipe smoking and occupational exposure, may explain gender differences in larynx cancer.

## Key findings

- Men had higher larynx cancer rates than women, even with similar smoking habits.
- Pipe smoking was more common in men and may contribute to cancer risk differences.
- Smoking prevalence decreased significantly in both sexes by 2020.

## Abstract

To study the importance of decreasing tobacco smoking on the occurrence of larynx cancer in men and women.

The incidence rates of larynx cancer in the Swedish population between 1970 and 2021 were retrieved from the Swedish Cancer Register for ages 50–84 years, stratified for sex, age and calendar year. Data on the population’s smoking habits was retrieved from surveys and from taxation on the sale of cigarettes. The occurrence of larynx cancer was compared to smoking habits, sex and age. The time trends were compared between larynx and lung cancer.

Over the years, Swedish men and women have had different smoking habits, especially older persons during the 1970s. In 1963, the prevalence of current smokers in women 50–69 years was 11%, while it was 46% in men. Around 2020, less than 10% of men and women in all age groups were current smokers. However, men had higher incidence rates of larynx cancer than women, even when their smoking habits were similar. For example, men and women 60–64 years of age in 2017–2021 had similar smoking habits during their life but the relative risk of larynx cancer in men compared to women was 3.3 (95% CI 1.7–4.8). However, pipe smoking was much more common in men.

The study indicates that other causes than cigarette smoking have an impact on the occurrence of larynx cancer in Sweden. Pipe smoking and occupational exposure to carcinogenic materials such as asbestos may be underlying causes of the difference in cancer risk between Swedish men and women.