No evidence for genetic link between height and testicular cancer

There is no evidence being tall causes an increased risk of testicular cancer, according to a new genetic analysis of more than 24,000 men.

Many previous studies have suggested that body measurements, particularly height, could be associated with a man’s risk of developing the disease.

However, research led by a team from The Institute of Cancer Research, London, and supported by the Movember Foundation, found no evidence that men who are genetically predisposed to being taller are at a greater risk of testicular cancer.

Instead, the team suggests there may be non-genetic factors, such as childhood nutrition, that influence both a man’s adult height and his disease risk, meaning any link between them would be indirect.

This could account for the studies that find a correlation between the two.

New search for a link

Writing in the journal Andrology, the team explained how they took a different approach to previous research in this area.

Rather than simply comparing recorded heights for men with and without testicular cancer, the team used a technique called Mendelian randomisation to assess whether genetic variants affecting height, and other physical characteristics, are more common in the group being researched – in this case, men with testicular cancer.

This strategy allowed the team to exclude non-genetic factors that may affect both height and disease risk.

The Molecular and Population Genetics team are investigating ways to optimise ‘next-generation’ sequencing technologies and analyses of these data in order to identify novel cancer predisposition genes.

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No causal association with height

Applying this approach to a dataset of genomes from more than 5,500 men with testicular cancer and 19,000 without – the largest dataset of its kind – the team found no evidence for a genetic relationship between a man’s adult height and his risk of developing testicular cancer.

They also did not find evidence for a link with other common body measurements such as body mass index (BMI), waist-to-hip ratio, and weight at birth.

The team did identify three genetic variants that seemed to be associated with both height and disease risk, but these are among almost 400 that are linked to height, and contribute only a little to the trait.

Dr Clare Turnbull, a Senior Researcher in the ICR’s Division of Genetics and Epidemiology who led the research, said:

“Risk of developing testicular cancer has doubled over the last three decades in Western countries but we don’t yet know why.

“There’s been a great deal of interest in the connection with physical traits, such as height. But our findings, based on the largest dataset of its kind, clearly show there is no causal association.

“The results suggest that the often observed association between height and testicular cancer, if true, may be due to the influence of environmental factors that affect both disease risk and height.

“Several have been proposed, from foetal nutrition to the age of onset of puberty, but more research is needed into these early life events to determine how they may fit into the bigger picture.

“Larger genetic studies in testicular cancer, along with advances in our approaches to linking and analysing health-related datasets, will enable additional interrogation of links between testicular cancer and other physiological or metabolic phenotypes.”