How Cancer Treatments Affect Fertility

The sad news is that today, one out of every three women and one out of every two men in the United States will get cancer at some point in their life. While cancer can have so many terrible physical and emotional effects on a patient, what comes as a shock to many people undergoing cancer treatment is that their diagnosis can have the long-lasting repercussions of infertility.

The treatments, more often than cancer itself, can interfere with some parts of the male reproductive system and affect a man’s ability to have children.  The effects on fertility depend on a number of factors, such as:

  • Your age
  • The types of treatment you undergo
  • The doses of drugs you are given
  • Your baseline fertility
  • The length of your treatment

Each cancer case is different, which means that everyone’s treatment plan and recovery time are different. Treatments may cause fertility problems affecting your ability to father a biologic child, including:

  • Inability to produce sperm.
  • Damage to nerves and blood vessels needed for erection and ejaculation.
  • Inability to produce hormones that stimulate sperm production.

Different types of treatments have different effects:

Chemotherapy:

Chemo kills rapidly-dividing cells in the body (cancer occurs when cells begin to divide uncontrollably without a way to stop). Because sperm cells divide quickly (and a man produces around 1500 every second), they are an easy target for damage such that chemotherapy  often reduces or stops sperm production. This will become permanent if all of the sperm stem cells are damaged to the point that they can no longer mature.

Hormone therapy:

Some hormone therapies are used to treat cancers that specifically affect the testicular region. Such drugs can lower a man’s sex drive, cause erectile problems, and affect sperm production and your ability to have a child. 

Radiation:

Radiation is an extremely common way to treat various cancers, using high-energy rays to kill cancer cells. When radiation is applied to specific parts of your body, and especially your testicles, pelvic region, and pituitary gland, the brain will no longer be able to signal the testicles to make sperm and testosterone and cause fertility problems. Even when the testicles are protected during radiation treatment, some radiation still may reach them and cause damage to your sperm.

 Bone marrow/stem cell transplant:

Having a bone marrow or stem cell transplant usually requires chemotherapy and radiation prior to the procedure (see above). Even so, these specific procedures may result in permanent infertility.

Surgery:

Surgery that removes both of the testicles stops sperm production forever. The surgical removal of a single testicle is a common treatment for testicular cancer. Removal of just one testicle to treat testicular cancer can lower the amount of sperm the body makes, but as long as a man has one healthy testicle, he can continue to make sperm after surgery.

Following cancer treatment, it is very possible for a man to regain the ability to produce sperm, though this generally takes between one and three years, and may only result in partial recovery (low sperm counts). There is no evidence that children conceived after cancer treatment are at increased risk for birth defects: However, during cancer treatment, many of the available sperm in your testicles are damaged, and it is important to maintain the use of birth control during treatment so that the damaged sperm are not used to inseminate.

For those men who do wish to be able to conceive after treatment, there are many possible options to maintain healthy samples of sperm:

Sperm banking:

Also known as cryopreservation, sperm banking is the easiest option for young men facing cancer treatment who would like to have children one day. Samples of semen are collected through masturbation, analyzed in a lab and then frozen for the future. These sperm can be frozen for an indefinite amount of time.

Testicular Sperm Extraction (TESE):

TESE is a surgical option when a man’s semen has no sperm, but it is possible that he still may have sperm production in the testicles. A surgeon will remove a small piece of testicular tissue. The sperm are extracted from the tissue and then frozen or used to inseminate his partner.

Testicular Shielding:

It is sometimes possible to protect the testicles from radiation during treatment. However, even with shielding, it is difficult to protect testicles from all radiation due to radiation scattering.

Finally, a new experimental procedure is being tested in order to allow prepubescent boys with cancer to maintain high sperm counts after cancer treatment. The treatment takes a sample of testicular tissue and turns sperm progenitor (precursor) cells into actual sperm cells. When these sperm cells are then put back into the testes, they multiply and repair normal sperm production. These precursor stem cells are found in prepubescent boys even though they haven’t experienced puberty yet. Though they have the stem cells, boys lack the ability to turn them into sperm. Putting the healthy, undamaged stem cells into the testes environment recreates the normal situation and promotes the nurturing of sperm stem cells until they become actual sperm.

References

“How Cancer Treatments Can Affect Fertility in Men.” American Cancer Society, American Cancer Society, 28 June 2017.

“Building Your Family After Cancer Treatment: Information for Men.” Memorial Sloan Kettering Cancer Center, Memorial Sloan Kettering Cancer Center, 29 May 2018.

“Male Fertility Issues and Cancer – Side Effects.” National Cancer Institute, 2 May 2019. 

Chan, Peter. “Fertility after Cancer in Men.” Canadian Urological Association Journal, vol. 3, no. 3, June 2009, pp. 223–224.

Mabe, Rachel. “A New Hope for Male Fertility After Cancer Treatment.” The Atlantic, Atlantic Media Company, 13 Oct. 2017.

“Fertility and Cancer.” Society for the Study of Male Reproduction (SSMR) | Fertility & Cancer | Information for Male Infertility Patients | SSMR.org.