Siblings of subfertile men at high risk of childhood cancer
Siblings of men with oligozoospermia are susceptible to any-site cancer and acute lymphoblastic leukaemia, according to a recent study.
To determine semen parameters associated with an increased childhood cancer risk in the family members of subfertile men, a retrospective cohort study was conducted in men from the Subfertility Health and Assisted Reproduction study who underwent semen analysis between 1994 and 2001. Researchers used fertile population controls from the Utah Population Data Base.
The primary outcome was the risk of any childhood cancer in the siblings and cousins of men who underwent semen analysis vs fertile, age-matched controls. Cox proportional hazard regression models were used to assess the association between semen quality and childhood cancer incidence.
There were 10,511 men with complete semen analysis included in the study, as well as an equal number of fertile controls. These men had a total of 63,891 siblings and 327,753 cousins.
There were 170 childhood cancers identified in siblings and 958 in cousins. The three most common cancers identified in siblings were acute lymphoblastic leukaemia (n=37), brain cancer (n=35) and Hodgkin lymphoma (n=15).
Siblings of subfertile men showed a twofold increased risk of any childhood cancer and a threefold increased risk of acute lymphoblastic leukaemia compared to fertile controls (hazard ratio [HR], 2.09; 95 percent CI, 1.18 to 3.69 vs HR 3.07; 1.11 to 8.46).
“This suggests a shared genetic/epigenetic insult or an environmental exposure that merits further investigation,” researchers said.
An earlier study suggested a connection between male infertility and selected cancer risk in relatives, stressing the possibilities of shared biologic mechanisms between the two diseases, exposure to environmental factors, and an increased level of genetic/epigenetic burden in subfertile men and their relatives that may be associated with risk of cancer. [Fertil Steril 2016;106:731-738]