Young infertile men are '50% more likely to develop aggressive prostate cancer'



Men who struggle to father a child while young are more than twice as likely to develop the most deadly form of prostate cancer when they age, research shows.

A study of more than 20,000 men revealed those classed as infertile by IVF doctors were up to 2.6 times more likely to go on to be diagnosed with the fast growing and spreading, hard-to-treat form of the disease as other men.

The finding suggests that the cancer and flaws in sperm production have a common origin - and that infertile men might want to consider being screened for the disease.

Men who are infertile when they are young are more likely to develop aggressive prostate cancer later in life, a study has found

Fleshing out the link could shed fresh light on the causes of the cancer and pave the way for new and better treatments.

Prostate cancer is the most common cancer among men and the second highest killer, after lung cancer. Some 35,000 people a year are diagnosed with it - and 10,000 die.

Two thirds of victims have a non-aggressive variety and can often lead a healthy life. But the aggressive version can rapidly be fatal.

The U.S. researchers compared the health records of 22,000 men who had been on the books of Californian IVF clinics, with those of men of a similar age from the general population.

Those diagnosed as infertile were no more likely to develop easy-to-treat, non-aggressive prostate tumours in later years than other men.

However, their odds of hard-to-treat cancers were 2.6 times higher, the journal Cancer reports.

Some previous studies concluded that the more children a man has, the lower his chances of the disease, but others have come to the opposite conclusion.

By studying men who were unable to have children, rather than those who chose not to, the researchers hoped to settle the argument.

The University of Washington team said it was unlikely their result could be explained away by infertile men simply being more conscientious about going for health checks.

Instead, the aggressive form of the disease and infertility may share a biological cause, such a flaws in the sex chromosomes, or faults in the way damaged DNA heals itself.

A previous study found that fathers of girls are more likely to develop prostate cancer, chiming with the idea that the chromosomes that determine a baby's gender have a role to play.

Dr Thomas Walsh, the author of the latest study, concluded: 'These results, if confirmed, also suggest that men identified with infertility earlier in life may be considered for prostate cancer screening, given the elevated risk specifically for high-grade disease.'

British experts stressed that more research was needed before recommending that infertile men be tested for signs of the disease.

Ed Yong, head of health evidence and information at Cancer Research UK, added: 'Research like this will eventually tell us more about the causes of prostate cancer, which are still largely unknown.

'It's unlikely that being infertile directly leads to prostate cancer. Instead, both infertility and a higher risk of prostate cancer might stem from a common genetic fault, or some aspect of our lifestyle or environment.'

Although it is known that men with a family history of the disease are at greater risk of developing it themselves, researchers have struggled to pinpoint the key genetic changes.

Age and diet also play a role, with the cancer being most common in older men and those who eat a fatty diet low in fruit and vegetables.

Exercise may be protective, with a recent study finding those who spend most of their working lives sitting down are almost 30 per cent more likely to be diagnosed with the disease than those with very active jobs.

Dr Helen Rippon, of The Prostate Cancer Charity, said: 'Being able to identify early and with confidence men who are at risk from a high grade, potentially life threatening prostate tumour from those who are likely to develop a slow growing form of the disease is one of the most important questions facing prostate cancer research today.

'This new study is one of the first to investigate if there is a possible link between male infertility and the risk of developing an aggressive prostate cancer.'

But she cautioned that the low number of men taking part in the study diagnosed with aggressive prostate cancer meant it was 'difficult to draw any firm conclusions about whether the suggested link does exist'.