Late Effects of Childhood Cancer Treatment

Late effects are health problems that show up months or years after cancer treatment ends. They come from the same treatment that cured the cancer. This can include chemotherapy, radiation, surgery, or a stem cell transplant. Not every survivor gets a late effect. But knowing what to watch for helps your family catch problems early, when they are easiest to treat.

Cancer treatment targets fast-growing cells. That is how it works against cancer. But a child's healthy tissue is also growing fast. So treatment can affect the heart, lungs, kidneys, bones, brain, and hormone glands. It can affect fertility later in life too. What shows up, and how bad it is, depends on three things. These are the type and location of the cancer, the specific drugs and radiation doses used, and the child's age at the time of treatment.

Heart problems can include a weaker heart muscle or an irregular heartbeat. These are more common after certain chemotherapy drugs or chest radiation. Brain and nervous system effects can include trouble with memory, learning, or focus. These show up more after treatment for brain tumors or leukemia. Hormone effects can include slower growth, early or delayed puberty, thyroid problems, or fertility issues. Bone, digestive, lung, and kidney effects are possible too, depending on treatment. Some survivors face a higher risk of a second, unrelated cancer later on. This can include leukemia or cancer of the thyroid, breast, lung, or skin.

Survivors of childhood cancer are more likely than their peers to be diagnosed with depression, anxiety, or post-traumatic stress. This is a real late effect, not a personal failing. Bring up mood, sleep, worry, or behavior changes at every follow-up visit. Treat it the same way you would bring up a new cough or headache.

Follow-up usually includes a yearly exam by a doctor who knows childhood cancer survivors. Depending on your child's treatment, this can include heart imaging, hearing tests, memory and learning tests, blood work, or imaging to screen for a second cancer. Mental health screening should be part of this too, not an afterthought. The exact schedule depends on what treatment your child had.

Some late-effect risk comes from treatment your child already received. That part cannot be changed now. But healthy habits still help. Regular exercise, a balanced diet, not smoking, and routine medical and dental care all support long-term health. These habits will not undo a treatment-related risk. But they can lower other risks that stack on top of it.

Ask your child's team for a written summary before treatment ends. It should list every chemotherapy drug and dose. It should list any radiation, including the exact dose and the body part treated. It should note any surgery. This document is the single most useful tool for managing late-effect risk over your child's whole life. Every new doctor, for decades to come, will use it to know exactly what to screen for.

The Children's Oncology Group runs a Late Effects Directory. It lists survivorship clinics across the country that specialize in childhood cancer survivors. These clinics know which late effects go with which treatments, and they follow published screening guidelines built specifically for survivors. If your child's hospital does not have its own survivorship clinic, ask for a referral to one that does.

A few of these need emergency care rather than a phone call. Call 911 or take your child to an emergency department if they have chest pain, faint or collapse, have a racing heartbeat that will not settle, get a sudden severe headache, or have bleeding you cannot stop. Heart damage from earlier treatment can appear years later, so chest pain in a survivor is checked urgently.

Call your child's survivorship team the same day for a new lump, unexplained bruising or bleeding that has settled, breathlessness during ordinary play, or new swelling. Most of the time these turn out to be minor. But because some late effects involve the heart or a second cancer, it is worth checking promptly instead of waiting.

Ask for a written list of your child's specific late-effect risks, based on their exact treatment. Ask what tests are recommended, and how often. Ask which symptoms should prompt a call between visits. Ask how this plan will change as your child gets older.

• National Cancer Institute — Late Effects of Treatment for Childhood Cancer (PDQ).