Late Effects of Childhood Cancer Treatment: Infertility
Whether your baby, toddler or young child who is currently caught up in the fight of their lives against cancer will eventually be able to have children or not is probably the last thing on your mind, but it may be something that you should take into consideration…
Some cancer treatments do not affect a child’s growing reproductive system, but others can damage a girl’s ovaries, which contain eggs, or a boy’s testes, which contain sperm. This damage may make it impossible to have a baby for a short period after completing cancer therapy or for the rest of the person’s life.
Chemotherapy, Radiation Therapy, and other cancer treatments can be very effective at doing their job, but what makes them good at fighting cancer can also cause side effects.
One of the side-effects of cancer treatments can affect the reproductive organs and have long-term effects on a child’s reproductive health. Side effects such as reduced fertility as a result of cancer treatments are known as late effects.
Your child’s risk of having late effects depends on his or her diagnosis, the type of treatment your child is getting, and the dosages. Everyone is different so it’s best to discuss the subject with your child’s medical team.
Your child’s doctor should be able to tell you whether their cancer treatment regimen is likely to have short- or long-term effects on your child’s reproductive health or not.
How Some Cancer Treatments Can Affect Fertility
Some Chemotherapy drugs are more likely to lead to infertility than others. Cytoxan (known generically as cyclophosphamide) is part of a group of chemotherapy drugs called alkylating agents. These are more likely to affect the reproductive organs when given in higher doses.
Other chemotherapy drugs and combinations of drugs also may affect your child’s fertility. There are many different chemotherapy drugs, so it is always best to ask your child’s doctor if the drugs he or she is taking will put them at risk for fertility problems.
Some of these drugs may cause short-term effects on a girl’s menstrual cycle, but do not cause early menopause. Sometimes, medications are used to put the gonads “to rest” during chemotherapy, so that they may be less likely to be damaged during treatment.
Treatment plans for paediatric cancers often use the lowest doses of alkylating agents possible, so the risk of permanent damage to the reproductive organs is lowered. For many cancers, alkylating agents are not used at all.
Radiation Treatments also can damage sperm and eggs, whether they are aimed directly or scattered.
If radiation is focused on or near the pelvic area, abdomen, spine, or whole body, it can:
- Damage a girl’s eggs and affect the release of female hormones (ovarian insufficiency), which may initially appear as irregular or no menstruation.
- In boys, radiation can also damage sperm and affect the release of male hormones, which may result in infertility during adulthood.
Some cancer treatments involve radiation to the head as a way to kill cancer cells that may be in the central nervous system. Sometimes this can injure the parts of the brain (and the pituitary gland) that make hormones that control puberty and the menstrual cycle. If that happens, doctors can give these hormones to a patient so he or she can have normal pubertal development, sexual function, and fertility.
These changes may gradually go away after treatment is stopped, but can be permanent.
Depending on the type and target area of treatment, it may be possible to shield the testes or ovaries from damage, or even move the ovaries out of the path of radiation (this is called transposition).
For patients who need surgery for cancer, doctors may sometimes need to remove part of the reproductive organs, depending on where the cancer is situated.
While we do understand that you will have more than enough to contend with upon finding out that your child has cancer, the subsequent tests and treatments, it is important for your child’s future that you take infertility into consideration as well.
Remission is the goal when treating cancer, but your child’s future quality of life should also be part of the healing process. It is therefore important that you discuss infertility with your child’s doctor, a nurse or a social worker involved in your child’s treatment.
Questions to Ask Your Child’s Doctor
- Could my child’s treatment plan affect his or her ability to have children?
- Will this treatment affect my child’s ability to go through puberty?
- For daughters: What are the chances this treatment will lead to early menopause? Can treatment affect some organs (like the lungs or heart) in a way that will increase the risk of problems during pregnancy or labour?
- Are there other treatments that are not as risky but just as effective?
- What options are available to preserve fertility before treatment begins? Will they affect how well the cancer treatment works?
- Would it be helpful to see a fertility specialist before treatment begins?
- I’m worried about the costs of preserving my child’s fertility. Who can help me with these concerns?
- After treatment, how will we know if my child’s fertility has been affected?
Talking to Your Child about Fertility
It is important that you discuss the risk of fertility side effects of cancer and its treatment with your child’s health care team, but it is also important that you discuss this with your child – in a way that is appropriate for his or her age and development.
Fertility is a complex idea, especially for children, but if a child is old enough to understand fertility before starting treatment, he or she should be involved in the discussion about how treatment may affect fertility.
It is important that you ask your child if he or she wants to have any procedures that are intended to help preserve fertility. Children and teens are not able to give full legal consent because of their age, however, a child who can understand must generally agree (called “assent”) before these procedures can be done.
Parents must also give consent before the procedure. Consent should only be given after you have been told about a procedure’s risks, potential complications, and success and failure rates.
Options for Preserving Fertility
Current fertility-preserving options are limited for children who are diagnosed with cancer before puberty, and costs can be very high.
Radiation therapy to the pelvic area may damage the uterus. Scarring from radiation therapy can slow blood flow to the uterus, which means that the uterus will not be able to enlarge during a pregnancy. This could make pregnancy difficult later in life or increase the risk of miscarriage and premature or low-birth-weight babies.
Sometimes, if radiation therapy is planned for the abdomen, the ovaries can be protected by surgically moving them away from the radiation area (this is called transposition).
If preventing damage to the ovaries is not possible, there are some other options, including freezing eggs, embryos, or ovary tissue. After a girl has gone through puberty (usually occurs between the ages of 9 and 15), she can have her eggs or embryos frozen.
- Embryo Freezing is a technique in which eggs are taken from the ovaries, fertilised in a laboratory, and then frozen and stored. This technique is not often used in girls and teens because it requires sperm from a partner or donor.
- Egg Freezing is a more practical and increasingly successful option. Experts are able to freeze eggs from girls as young as 12. This method requires about 2 weeks of fertility drug treatment, so girls who need to start cancer treatment right away cannot freeze mature eggs.
When there is not enough time for ovarian stimulation, eggs can be collected with brief or no medication treatment. This yields immature eggs that need to be matured in a laboratory. This is called in vitro maturation and is being investigated. Success rates with this method are lower than when you freeze mature eggs with full ovarian stimulation.
- Ovary Tissue Freezing & Transplantation: It is not practical to perform ovarian stimulation to freeze eggs in girls who have not gone through puberty. One way to preserve fertility is to freeze ovary tissue in girls who have not gone through puberty and then transplant it later in life.
One experimental procedure involves removing ovary tissue and freezing it for future use. This is usually done with outpatient laparoscopic surgery and takes about an hour. Laparoscopy uses a thin, lighted tube called a laparoscope, which is inserted through a small incision in the abdominal wall to remove ovary tissue; the tissues can be transplanted back into the pelvis during an outpatient procedure. If the surgeons do not think the pelvis is best for transplantation, tissues can even be transplanted under the skin. This method is sometimes called ovarian cryopreservation.
This technique is relatively new, so only a limited number of experts offer ovarian tissue freezing around the world. The technique may not be recommended for some types of cancer due to the fact that the ovarian tissue may contain cancer cells. A fertility specialist who has experience in ovarian tissue freezing and transplantation should determine whether you or your child is the right candidate for this procedure.
If your daughter’s cancer treatment has a low risk of affecting fertility, you may also decide not to take any action.
It is possible to prevent or lower the risk of damage in boys, too. For example, if your son is getting radiation therapy, his testicles could be shielded. There are a few other fertility options available, including sperm banking, testicular tissue freezing, and sperm aspiration.
- Sperm Banking: Sperm banking, also called cryopreservation, is a common, non-invasive option that is only possible for boys who have already gone through puberty (most boys have some sperm in their semen by about age 13). Sperm are collected and frozen then stored in a special facility. Some hospitals have sperm bank programs and there are also clinics that specialise in sperm banking.
- Testicular Tissue Freezing: Boys who have not gone through puberty may be able to save sperm by freezing testicle tissue. This is an experimental approach and is still being studied, so its chance of success is not known. Some tissue from the testicles is collected and frozen. Hopefully, the tissue contains stem cells that will later produce mature sperm. The thawed tissue might then be put into the young man’s testicle. Alternatively, stem cells might be taken out of the frozen tissue and injected into the testicle.
Currently, all of these options are still being investigated; there have been no reports of testicular transplants in patients.
Your child’s doctor may advise against tissue freezing for some types of cancer, because frozen testicle tissue could carry cancer cells back into the body.
- Sperm Aspiration: This is another option that is being studied for boys who have not gone through puberty. During this procedure, immature sperm cells are removed and stored for future use. The sperm would then be used to fertilise an egg in the laboratory by in vitro fertilisation (IVF). After IVF, the fertilized embryo is put into a woman’s uterus.
You may also decide not to take any action to preserve your son’s fertility if cancer treatment has a low risk of affecting fertility.
Many boys go through puberty after cancer treatment and are able to have children naturally. After puberty starts, a doctor can check your son’s semen to see if he is making sperm.