Men who conceive with assisted reproduction at increased prostate cancer risk

Men who conceive children using assisted reproduction techniques (ART) like in vitro fertilization (IVF) are more likely to develop prostate cancer and may benefit from screening, a recent study suggests.

Researchers examined data on 1.18 million Swedish fathers, including almost 21,000 who conceived using IVF and nearly 15,000 who used a technology known as intra-cytoplasmic sperm injection (ICSI) to conceive.

Compared to men who conceived naturally, those who used IVF were 33% more likely to develop prostate cancer and men who used ICSI were 64% more likely to develop prostate cancer.

“We do not believe that the fertility treatments themselves cause or increase the risk of prostate cancer,” said Yahia Al-Jebari, a researcher at Stanford University in California who led the study.

“Instead, we believe it is likely the underlying infertility which is linked with prostate cancer,” Al-Jebari, who completed the research at Lund University in Malmo, Sweden, said by email. “The full extent of the male’s participation in most fertility treatments is only to supply a semen sample, thus, the fertility treatment has no physical effect on the male patient and is unlikely to cause prostate cancer.” Men who conceived with ART were also nearly twice as likely to develop prostate cancer before age 55, researchers report in the The BMJ.

With ICSI, men were 86% more likely to develop prostate cancer before their mid-50s than men who conceived naturally, and those who used IVF were 51% more likely to have prostate cancer at younger ages.

All of the men in the study fathered babies between 1994 and 2014. Men who conceived naturally were 32 years old, on average, when they became fathers, compared with an average age of 37 for men who conceived using ART.

Among men who conceived naturally, 3,244, or 0.28%, developed prostate cancer. That compares with 77 men, or 0.37%, in the IVF group and 63, or 0.42%, in the ICSI group.

One limitation of the study is that it only included men who used ART to successfully conceive a child, not men whose efforts to conceive with ART failed, the study team notes. This makes it possible that the most severe cases of infertility were not part of the study.

Poor sperm function causes nearly half of all infertility cases, Aditi Sharma of Imperial College London and Channa Jayasena of Imperial College Healthcare NHS Trust in the UK write in an accompanying editorial. It’s possible that poor sperm function could be a marker for future disease, including prostate cancer.

However, the study results alone aren’t enough evidence of a link between infertility and prostate cancer to recommend different screening or treatment approaches targeting men who conceive with IVF, according to the editorial.

“Screening is controversial owing to lack of survival benefit and the harms from overdiagnosis,” the editorial notes. “In the absence of a plausible mechanism of action or proof of causation, justifying screening for prostate cancer in all infertile men is difficult.”