Male infertility: a biomarker of individual and familial cancer risk.

Associations between male infertility and cancer are gaining clinical attention. Relationships between infertility and cancer have traditionally been studied in women, but recent work has focused on the male component of reproduction. Infertile men are at an elevated risk to develop various malignancies later in life, primarily genitourinary malignancies such as testicular and prostate cancer. Rates of testicular and high-grade prostate cancer in infertile men appear to be at least double the risk in the general population. The link between infertility and malignancy highlights the importance of thorough evaluation and long-term follow up-beyond a simple semen analysis. A detailed urologic evaluation, possibly including scrotal ultrasound, may be beneficial to screen infertile men for testicular cancer. Publications have also demonstrated that male infertility can be a biomarker for cancer risk in first- and second-degree relatives. Testicular cancer risk in first-degree relatives of infertile men is 52% higher than the risk in relatives of fertile control men, and male infertility has been associated with a two- to threefold elevation in risk of childhood cancer in the siblings of infertile men. Links between infertility and malignancy are multifactorial, and exact mechanistic explanations are still not fully understood. Although more studies are needed to assess levels of risk and create screening recommendations in this population, understanding the relationship between male infertility and malignancy is crucial to provide comprehensive counseling for infertile men and their families.