# Sex hormones and risk of lung and colorectal cancers in women: a Mendelian randomization study

## TL;DR

This study investigates the link between sex hormones and lung and colorectal cancer risk in women using genetic data, but finds limited evidence for a causal relationship.

## Contribution

The study uses Mendelian randomization to explore sex hormone effects on cancer risk in women, providing new genetic insights.

## Key findings

- Higher testosterone levels were linked to lower lung non-adenocarcinoma risk in one study, but not in larger data.
- No strong evidence was found for a causal role of sex hormones in lung or colorectal cancer risk in women.
- Results highlight the need for further research on sex hormone-cancer relationships in women.

## Abstract

The roles of sex hormones such as estradiol, testosterone, and sex hormone-binding globulin (SHBG) in the etiology of lung and colorectal cancers in women, among the most common cancers after breast cancer, are unclear. This Mendelian randomization (MR) study evaluated such potential causal associations in women of European ancestry. We used summary statistics data from genome-wide association studies (GWASs) on sex hormones and from the Trøndelag Health (HUNT) Study and large consortia on cancers. There was suggestive evidence of genetically predicted 1-standard deviation increase in total testosterone levels being associated with a lower risk of lung non-adenocarcinoma (hazard ratio (HR) 0.60, 95% CI 0.37–0.98) in the HUNT Study. However, this was not confirmed by using data from a larger consortium. In general, we did not find convincing evidence to support a causal role of sex hormones on risk of lung and colorectal cancers in women of European ancestry.