What is normal male fertility, and how is it affected by cancer treatment?
Normal male fertility is associated with the production of healthy sperm. Healthy sperm is defined by:
- Sperm count (or, the number of sperm in the semen),
- Sperm motility ([pause] how much movement and activity sperm has), and
- Morphology (or the shape of the sperm themselves).
Cancer and cancer treatment can affect sperm and cause infertility in men. Though the cancer itself can contribute to infertility, cancer treatment is most commonly to blame.
Cancer treatments including chemotherapy, radiation, and surgery can threaten a man's fertility.
Chemotherapy kills rapidly dividing cells like cancer cells, but also including sperm and cells that make sperm. Certain chemotherapy drugs are more damaging than others, with alkylating agents causing the most damage. These agents often reduce or eliminate sperm count during and after treatment.
Radiation therapy can also affect a man's fertility, depending on which part of his body is treated. Total body radiation or radiation of the testicles can cause infertility.
Radiation to hormone-producing areas of the brain may also impact fertility by blocking normal hormone production.
Surgery that removes all or part of the reproductive system, such as one or both of the testicles, can lead to infertility. Certain surgeries may cause nerve damage that can affect the ability to ejaculate. The location and type of surgery influences the risk to fertility.
Some or all of these treatments may not only affect the quantity of a man's sperm, but also the quality. Aside from low sperm counts, misshapen sperm or sperm with low motility may affect a man's fertility.
A man's fertility can best be preserved by obtaining a semen sample prior to radiation or chemotherapy. Even if there is a low sperm count or other concerns, banking sperm before starting treatment is an easy and helpful strategy if a man's fertility should be affected by his cancer treatment.
Not all cancer treatments impact fertility the same way for all men. It is important to talk with a doctor to determine which cancer treatments are available and to understand how those treatments might affect a man's fertility.