Cancer risk in first- and second-degree relatives of men with poor semen quality.

OBJECTIVE: To further characterize the association of male infertility with health risks by evaluating semen quality and cancer risk in family members.

DESIGN: Retrospective, cohort study.

SETTING: Not applicable.

PATIENT(S): A total of 12,889 men undergoing SA and 12,889 fertile control subjects that had first-degree relative (FDR) data (n = 130,689) and 8,032 men with SA and 8,032 fertile control subjects with complete second-degree relative (SDR) data (n = 247,204) were identified through the UPDB. An equal number of fertile population control subjects were matched.

INTERVENTIONS: None.

MAIN OUTCOME MEASURE(S): Adult all-site, testicular, thyroid, breast, prostate, melanoma, bladder, ovarian, and kidney cancer diagnoses in FDRs and SDRs.

RESULT(S): The FDRs of men with SA had a 52% increased risk of testicular cancer compared with the FDRs of fertile population control subjects. There was no significant difference in testicular cancer risk for the SDRs based on any of the semen parameters. The FDRs and SDRs of azoospermic men had a significantly increased risk of thyroid cancer compared with fertile population control subjects.

CONCLUSION(S): These data suggest a link between male infertility and selected cancer risk in relatives. This highlights the possibilities of shared biologic mechanisms between the two diseases, exposure to environmental factors, and an increased level of genetic and/or epigenetic burden in subfertile men and their relatives that may be associated with risk of cancer.