Researchers based at the Institute of Cancer Research have discovered a link between infertility and breast cancer in men. This could help us better understand the disease and lead to better ways to treat or prevent the disease.

A male researcher with short brown hair sits at a desk in a white labcoat while making notes

Understanding male breast cancer

Researchers, funded by Breast Cancer Now, have discovered that men who report issues with fertility may be more likely to develop breast cancer than men who have no issues with fertility.

This study is part of the Breast Cancer Now Male Breast Cancer Study, which was established to pinpoint the precise genetic, environmental and lifestyle causes of breast cancer in men.

These findings could pave the way for more research to better understand what causes breast cancer in men, so that we can find new ways to prevent and treat the disease.

Studying breast cancer in men

Around 370 men are diagnosed with breast cancer each year in the UK. It is rare, but by studying larger groups of men over a long period we can better understand the disease and potentially find new ways to prevent or treat the disease.

Dr Michael Jones and his team at the Institute of Cancer Research, London, studied 1,998 men who were newly diagnosed with the disease in England and Wales over 12 years.

The participants were asked whether they had biological children or if they or their partners had ever had problems conceiving children. This included whether they had visited a doctor or clinic for fertility concerns.

The researchers also factored in other known risk factors for infertility and breast cancer that could affect the results of the analysis including alcohol consumption, smoking, family history of breast cancer and liver disease.

The link to fertility

Michael and his team discovered that men diagnosed with breast cancer were more likely to report an issue with fertility. They also found that men with no children were more likely to be diagnosed with breast cancer.

Supporting this, they also found there were significantly more men with no children among those who had been diagnosed with breast cancer – both overall and after restricting the analysis to married men only.

‘These are important findings linking infertility to breast cancer in men. Our study suggests that infertile men may be twice as likely as those without fertility issues to develop breast cancer,' explained Dr Michael Jones, who is Senior Staff Scientist in Genetics and Epidemiology at The Institute of Cancer Research, London.

'The reasons behind this association are unclear, and there is a need to investigate the fundamental role of male fertility hormones on the risk of breast cancer in men. We hope this could lead to insights into the underlying causes of male, and possibly even female, breast cancer.’ 

Next steps

The biological reasons why infertility may increase a man’s risk of breast cancer are not well understood. The researchers hope that these findings could provide the ground for further work that looks to understand the link between testosterone production and oestrogen exposure for men who develop breast cancer.

This could help us understand what causes the disease in men, so that we can find new ways to prevent and treat the disease.

Dr Simon Vincent, Director of Research, Support and Influencing at Breast Cancer Now, added: ‘Research has discovered different treatments directed at some features of breast cancer in women, however, breast cancer is not as well understood for men. This is why Breast Cancer Now funds the Male Breast Cancer Study which looks at what might cause the disease in men.

'Discovering a link between infertility and male breast cancer is a step towards us understanding male breast cancer and how we could find more ways to diagnose and treat men – and possibly women – with this devastating disease.’

This research is part of the Male Breast Cancer Study, launched by Breast Cancer Now in 2007, and the study was published in the journal Breast Cancer Research.


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