Fertility Questions for Childhood Cancer Survivors

No honest answer about fertility can be given in general. It depends on which drugs the child received, how much of each, and where any radiation was aimed. So the first thing to find is not an article. It is a treatment summary.

A treatment summary lists every chemotherapy drug and its total dose, every radiation field and dose, every surgery, and whether there was a stem cell transplant. The Children's Oncology Group publishes a standard form for this. It also publishes the Long-Term Follow-Up Guidelines, which are organized by exposure. You look up what the survivor actually received, and the guideline says what to watch for.

If nobody has handed you that summary, ask for it now. Call the treating hospital's survivorship clinic or medical records office. Do it before the survivor changes doctors, moves, or ages out of pediatric care.

Two groups of chemotherapy drugs account for most fertility damage.

Alkylating agents are the main group. St. Jude names busulfan, carmustine, chlorambucil, cyclophosphamide, ifosfamide, lomustine, mechlorethamine, melphalan, and procarbazine. NCI calls these high risk because they harm the cells that make sperm and the cells that hold eggs. Risk rises with the total dose and with the number of these drugs used together.

Heavy metal drugs are the second group. Cisplatin and carboplatin belong here.

Radiation matters by target. Radiation to the pelvis can damage the ovaries or testes directly. Radiation to the brain is a different problem. It can injure the pituitary gland, which sends the hormone signals that start puberty and keep the ovaries and testes working. Total body irradiation before a transplant hits both at once.

One detail explains a lot of confusion. Sperm-forming cells are very sensitive to chemotherapy and radiation. The cells that make testosterone are tougher, and usually fail only at high doses. That is why a young man can go through puberty normally and still have no sperm.

This is the split families most often miss.

A child who has not been through puberty cannot bank sperm or freeze eggs. There are no mature eggs or sperm to collect yet. The option is tissue.

For girls, that means ovarian tissue cryopreservation. St. Jude describes it as usually removing one ovary and freezing it for later use. For boys, that means testicular tissue cryopreservation. NCI notes that this is still offered through clinical trials, not as routine care. If a young child is about to start high-risk treatment, ask directly whether a tissue protocol is open at your center or at another one.

A teen who has been through puberty has more choices. A young man who can give a sample may bank sperm. NCI calls sperm banking the most common method, and samples can be stored for years. If he cannot ejaculate, sperm can sometimes be taken from the testis by a small procedure.

A young woman who has had at least one period may freeze eggs, though St. Jude's guide says this needs at least 14 days before treatment starts, for hormone medicine to ripen the eggs. Embryo freezing needs sperm from a partner or donor, and St. Jude's guide sets a minimum age of 18.

Two more options do not bank anything. Ovarian transposition is surgery that moves the ovaries out of the radiation field. Shielding places protection over the ovaries during radiation. Both must be decided before radiation begins.

Almost every preservation option must happen before treatment starts. Sperm banking, egg freezing, tissue removal, and ovarian transposition all lose their window once chemotherapy is in.

NCI reports something worth telling parents who feel rushed. Survivors were less regretful if they had met with a fertility specialist, whether or not they chose to preserve anything. The meeting itself has value. It is reasonable to ask the oncologist for that referral on the day of diagnosis, and to ask whether treatment can safely wait the days it would take.

After treatment, testing describes the current picture. It does not promise a future one.

For a young man, the direct test is a semen analysis, which counts sperm and looks at how they move. Blood tests for testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) fill in the hormone side. St. Jude recommends yearly checkups for at-risk boys, with growth and puberty tracked, plus these blood tests.

For a young woman, blood tests include FSH and anti-Mullerian hormone (AMH), which reflects how many eggs remain. Imaging of the ovaries and uterus may be added.

Numbers can move. A man with no sperm a year after treatment sometimes recovers sperm production later. A woman with normal hormone levels at 20 may still reach menopause early. So test results answer "now," not "ever."

A survivor can be fertile and still need hormone treatment, or be infertile with normal hormones. Keep the two questions apart when you talk to the clinic.

Primary ovarian insufficiency means the ovaries stop making eggs and estrogen too early. Without estrogen, bone strength drops and periods stop. St. Jude notes that a survivor whose ovaries do not work well may need medicine to replace the hormones the ovaries are no longer making.

On the male side, low testosterone is treatable. St. Jude lists patches, injections, and topical gel. Boys who had both testicles removed should see an endocrinologist regularly, starting around age 11.

Nothing on this list is an emergency. All of it is worth a call rather than a wait.

• Call your care team within a day or two if menstrual periods become irregular or stop, or if hot flashes, night sweats or vaginal dryness begin at an age when menopause would not be expected. NCI lists these among the signs of primary ovarian insufficiency, and estrogen loss affects bone strength as well as fertility.
• Call your care team within a day or two if low energy, flat mood, or loss of interest in sex has settled in and will not lift. Low testosterone is treatable, and so is depression, but neither gets sorted without saying it out loud.
• Ask for a survivorship appointment if a girl shows no signs of puberty by age 13, or if puberty stalls once it has begun, or a boy shows no signs of puberty by age 14. Those are the ages at which the Children's Oncology Group guidelines and St. Jude suggest hormone testing and a specialist referral. Do the same after a year of trying to conceive without success, or six months if the woman is older than 35, which is how NICHD defines infertility.

Young children need almost nothing. "The medicine works on fast-growing parts of the body, so we will keep checking that everything grows the way it should" is enough.

School-age children can hold a simple frame. Some treatments can make it harder to have a baby later, and doctors check on that as you grow.

Teenagers deserve the real conversation, and they should get part of it alone. Many teens will not raise it in front of a parent. Ask the clinic to schedule private time. A survivorship visit is also the moment to ask who takes over these questions in adult care, and to get the treatment summary into the teen's own hands.

For the wider picture, see Late Effects of Childhood Cancer Treatment and Childhood Cancer Late Effects: Questions for Follow-Up. For decisions before treatment starts, see Fertility and Cancer: Options Before Treatment and Fertility and Cancer Treatment. Related pages include Feeding and Appetite Changes in Childhood Cancer and Talking to Teachers About Childhood Cancer.

• Fertility Issues in Girls and Women with Cancer, National Cancer Institute
• Fertility Issues in Boys and Men with Cancer, National Cancer Institute
• Late Effects of Treatment for Childhood Cancer (PDQ), National Cancer Institute
• A Conversation on Oncofertility, National Cancer Institute
• Survivorship and Long-Term Follow-Up Guidelines, Children's Oncology Group
• COG Long-Term Follow-Up Guidelines, Version 6 (PDF)
• Male Reproductive Issues in Childhood Cancer Survivors, Together by St. Jude
• Infertility in Female Childhood Cancer Patients, Together by St. Jude
• Understanding My Fertility: A Guide for Females, Together by St. Jude
• Fertility After Childhood Cancer: Can I Have Children? Together by St. Jude
• About Infertility and Fertility, NICHD