Study: Infertile men at greater risk of developing breast cancer

By Mark Waghorn and Tom Campbell via SWNS

Infertility causes breast cancer in men, according to new research.

It doubles risk of the disease compared to peers with higher sperm counts.

The finding is based on around 2,000 newly diagnosed British men over a 12-year period.

It offers hope of better treatments. Underlying factors like hormone imbalances could be fueling the tumors.

Breast cancer is the most common cancer in women. In the UK, around 55,500 new cases are diagnosed every year.

But for men, it does not even feature among the top 20. Only a few hundred cases are recorded annually.

It has been largely overlooked - with only one previous study suggesting a possible link with being able to have children.

Lead author Dr. Michael Jones, of The Institute of Cancer Research, London, said: "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."

"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.

"Breast cancer is often thought of as something that only affects women, but men can also be diagnosed with the disease.

"Compared with previous studies our study of male breast cancer is large. It was carried out nationwide across England and Wales and was set in motion more than 15 years ago.

"Because of how rare male breast cancer is, it took us over 12 years to identify and interview the nearly 2,000 men with breast cancer who were part of this study."

The researchers interviewed 1,998 men living in England and Wales who were diagnosed with breast cancer between 2005 and 2017.

They compared their results with 1,597 men who were not blood relatives.

Men who reported infertility faced a significantly higher chance of having invasive breast cancer, where cancerous cells have already spread, the researchers found.

Whether a partner suffered from infertility, on the other hand, did not have any influence on whether they developed cancer.

A greater number of males with breast cancer also reported not having any children, 383 compared to 174, the researchers found.

However, this could be because some men choose not to have children for a range of cultural or social reasons, they caution.

Also not having children or being infertile was not found to increase the chances of breast cancer which had not yet spread to the surrounding tissue.

Dr. Simon Vincent, Director of Research, Support and Influencing at Breast Cancer Now, said: "Many people don't realize that men can get breast cancer, because incidence is much lower in men than women.

"However, every year in the UK around 370 men are diagnosed with breast cancer, and around 80 men die from it and it’s vital that we support anyone affected by breast cancer.

"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."

"Importantly, we hope the knowledge we have gained from this study reaches more men who might benefit from being aware of male breast cancer.

"Anyone seeking information and support can speak to Breast Cancer Now's expert nurses by calling the charity's free Helpline on 0808 800 6000."

Other factors like people's alcohol consumption, smoking and family history of cancer breast and liver disease, were examined by the researchers.

None of these were found to have influenced their findings, although they did not account for obesity.

They did however exclude men who were severely obese from the study, as well as some who had been previously been diagnosed with cancer or had testicular diseases like Klinefelter syndrome.

Relying on people to report on fertility can also prove challenging as it is a complex process which can involve men and women.

Men may prefer not to report children outside of a marriage or might not be aware that they have them.

Validating infertility with medical records could help overcome some of these challenges in future research.

Former police officer Dave, 64, from Bristol, who now runs his own IT company, was diagnosed with breast cancer in 2015.

He said: "I was on holiday in Florida, celebrating my birthday, when I found a lump on my chest in the shower. It wasn’t painful and I didn’t tell anyone about it because life just seemed normal.

"I wasn't aware that men should check for breast cancer, but I know that if your body changes, you shouldn’t leave it so I went to see my GP as soon as I got home and they referred me to see a specialist consultant."

"Despite being told it was probably just a fatty deposit, I had an ultrasound and biopsy. One week later I was diagnosed with breast cancer. The tumor was the size of a golf ball.

"Of course, when I was first diagnosed I was scared and it was tough to tell my children. I had a mastectomy, treatment and almost seven years later I am in good health and still receiving a course of drugs that can reduce the rate of cancer returning.

"My mother died from ovarian cancer when she was 68-years-old, and I knew there was a link between ovarian and breast cancer, but generally little is known about male breast cancer.

"People will say 'I didn't realize men could get that' and to be honest, I didn't think I would ever get it!

"It's really interesting that if you're affected by fertility issues, you could be more likely to be affected by breast cancer.

"I'm lucky that I haven't been impacted by fertility problems, but it's important scientists build on Breast Cancer Now's research as it could help to find out what causes some male breast cancers and one day even lead to developing new treatments."

The findings, published in Breast Cancer Research, are part of the wider Male Breast Cancer Study.

It was launched by Breast Cancer Now in 2007 to pinpoint the genetic, environmental and lifestyle causes of breast cancer in men.

The aim is to help identify those at risk and understand what can be done to lower their chances of developing the disease.

There are around 11,500 breast cancer deaths in the UK every year, or around 32 every day.

Dr. Jones added: "The causes of breast cancer in men are largely unknown, partly because it is rare and partly because previous studies have been small.

"The evidence presented in our study suggests that the association of infertility and breast cancer should be confirmed with further research and future investigations are needed into the potential underlying factors, such as hormone imbalances."