How Cancer Treatment Can Affect Fertility in Men

Cancer treatments can affect a man’s ability to father a child, particularly if those treatments are designed to address a malignancy of the male reproductive system. This can occur in one of three ways. First, damage to the endocrine glands or endocrine-related organs, such as the thyroid, adrenal glands and testes, can interfere with the production of hormones that control fertility. Second, damage to the pituitary gland in the brain can prevent the release of hormones that stimulate the testes to produce sperm and testosterone, both of which are required for male fertility. And third, in rare situations, such as in the case of advanced testicular cancer, the removal of an entire reproductive organ may be necessary.

In some men, cancer treatment may slow or temporarily stop sperm production; in others, it can lead to permanent infertility. In general, the risk of long-term or permanent infertility increases with higher doses of chemotherapy and radiation therapy. A man’s risk level can be influenced by other factors as well, such as his age and any existing fertility issues. Certain cancers can also cause men to have poor sperm quality, even prior to treatment.

The following cancer treatments can have fertility-related side effects:

• Chemotherapy – Chemotherapy is effective for cancer treatment because it targets and destroys rapidly dividing cells. Much like cancerous cells, some healthy cells in the body are constantly reproducing as well. These include the germ cells in the testes, which produce sperm. Because chemotherapy cannot distinguish between healthy cells and cancerous cells, the germ cells may be inadvertently targeted during treatment, and infertility can sometimes result.
• Radiation therapy – If radiation is delivered directly to the testicles, a decreased sperm count or sterility can occur. Fractionation is a technique that is often used to reduce the side effects of radiation by dividing a total dose into multiple smaller doses. However, multiple small doses of radiation can sometimes cause more damage to sperm than a larger, single dose. If the testicles are not the primary treatment target, shielding can be used to protect them from the effects of radiation therapy.
• Surgery – If cancer treatment involves the surgical removal of both testes, a man’s fertility will be affected because he will no longer be able to produce sperm. Additionally, surgery performed on the prostate, bladder, urethra or colon can sometimes result in a condition known as retrograde ejaculation, which causes the semen to enter the bladder instead of exiting the penis. While not medically harmful, this condition will affect a man’s fertility.

Researchers are continually developing and evaluating new cancer treatment options, including novel chemotherapy drugs and drug combinations. Several promising treatments are currently under study, and their effects on male fertility are not yet fully understood.

If you have questions about cancer treatment or its possible effect on your fertility, you can speak with a cancer expert at Moffitt Cancer Center. Call 1-888-MOFFITT or complete a new patient registration form online. We do not require referrals.