Men who have had fertility treatment to assist conception in the past have a higher risk of developing prostate cancer, a Swedish cohort study has reported.
Researchers found that men with infertility were more likely diagnosed with prostate cancer in the years after fertility treatment, and were more prone to develop the disease at a young age, when compared with fathers who conceived naturally.
'This large register-based study show men fathering children through assisted reproduction have a 30 to 60 percent increased risk of prostate cancer compared with men conceiving naturally,' said study first author Yahia Al-Jebari at Lund University in Malmö, Sweden.
She added: 'So the benefits of prostate cancer screening should be considered for this group.'
The study, published in the British Medical Journal, analysed data from all registered men who fathered a child between January 1994 and December 2014 in Sweden. Among almost 1.2 million births, about three percent resulted from IVF or ICSI (intracytoplasmic sperm injection).
Overall, few of the men in the treatment-group developed prostate cancer (0.37 percent in the IVF group and 0.42 percent in the ICSI group), however the risk was increased compared with the non-treatment group (0.28 percent). This translated to a 30 percent increased risk with IVF, and a 60 percent increased risk with ICSI of developing prostate cancer compared with men who did not undergo assisted reproduction.
Furthermore, the average age when fathers were diagnosed was lower among men who had used IVF or ICSI - at under 55, compared with an average age of 57 in the men who had conceived naturally.
Importantly, scientists warn that the results of this study are not due to cause and effect, but more likely hint at a shared cause underlying male infertility and prostate cancer.
Professor Allan Pacey at the University of Sheffield praised the study's use of big data to answer questions in male reproductive health. 'Perhaps all men who are diagnosed with a fertility problem in their 20s and 30s should be given a leaflet explaining what this might mean for them in their 50s and 60s, so that they can be aware of possible future problems, and be encouraged to visit their GP a bit quicker than they often do,' he said.
Others were cautious over the young age of the fathers at the end of the study (the average age at follow-up was 45). 'Prostate cancer is more common in men over the age of 50. The men involved in this study were younger on average, and therefore already have a very low risk of prostate cancer,' warned Simon Grieveson at Prostate Cancer UK. 'This study would need to look at a much broader age range to fully understand whether men who undergo fertility treatment actually have a higher risk overall.'
He added: 'We believe it's important that all men are aware of the risks of prostate cancer, and men concerned about the disease should speak to their GP. However, couples considering fertility treatment should not be put off by these results.'