Today 80 percent of children with cancer survive for five years or longer after their diagnosis, and most young survivors grow up to lead long lives. But many deal with after-effects of cancer for their entire lifetimes. Nearly three-quarters of these childhood cancer survivors will later develop a chronic health problem as a delayed effect of treatment, making long-term health monitoring critical to their well-being.
Pediatric endocrinologist Charles Sklar directs Memorial Sloan Kettering’s Long-Term Follow-Up Program, which has screened and managed the health of about 2,000 pediatric cancer survivors since its launch in 1990. Dr. Sklar is an active participant in a national research group known as the Childhood Cancer Survivor Study, which monitors the health of pediatric cancer survivors into adulthood to analyze the late effects of cancer treatment and determine how to better detect and treat them.
In a recent interview, Dr. Sklar discussed the Long-Term Follow-Up Program’s role in raising awareness of these lingering effects and why lifelong vigilance is essential.
Are parents of pediatric survivors typically prepared for dealing with late effects of treatment that can impact their child long-term or for the rest of their lives?
Most families that come to us now have heard of these effects, which is somewhat different than when our program started. Oncologists typically discuss most of these potential late effects at the time of diagnosis.
That being said, when you’re the parent of a child with a life-threatening illness, there’s only a limited amount of information you can take in. And often the survivors themselves are not aware because they may have been very young at the time of diagnosis, so these aren’t things that were necessarily discussed with them directly. That’s something we often need to do when we see them in our clinic.
What are the most common delayed effects of cancer treatment such as chemotherapy or radiation on children?
It’s difficult to generalize because treatments are very different for different diseases, and younger children have different vulnerabilities compared to older children. Endocrine, growth, and reproductive problems are very common. Heart and lung problems certainly do occur, but only in select groups of people, and there are very few people who actually suffer from clinically important heart or lung impairments.
How do you diagnose and treat late effects?
Every patient gets a tailored treatment summary that looks at all the therapies they received – including the types and doses of chemotherapy or radiation – as well as the patient’s gender and age at the time of treatment.
We develop a care plan based both on our own experience as well as published guidelines we were instrumental in developing, and we begin a screening program. Some screenings require a yearly blood test; specialized testing like echocardiograms or pulmonary function testing; or sending patients to experts for tests such as neurocognitive testing.
If the tests continue to be normal, there’s obviously nothing to do but continue the screening. Along the way we educate families and survivors about the need to do many of these tests for the rest of their lives.
If we see abnormalities in our screening tests, we treat them or send the patients to specialists who can treat them or perhaps follow them with more sophisticated testing.
How has research on late effects of cancer treatment changed the way that pediatric cancer patients are now treated after their initial cancer diagnosis?
Many changes in treatment have been informed by these types of studies. It’s important to understand that the full scope of late effects and a complete understanding of their prevalence can take 20 to 30 years to come about, so there’s a lot we don’t know yet.
But now we do know, for example, that radiation to the brain – which used to be a standard treatment for almost all children with leukemia – put these children at risk for learning, growth, and endocrine problems. Today, radiation to the brain is only given to a very tiny fraction of children with leukemia, the most common cancer that we see in children.
Radiation to the chest, particularly for young women with Hodgkin’s disease, has now been associated with a very high risk of breast cancer as well as heart problems for both men and women. So the volume, dose, and even the use of radiation has been reduced among these patients over the last 20-plus years.
Are there any new findings from the Childhood Cancer Survivor Study that you find especially compelling?
One study just coming out looked at the interaction between traditional cardiovascular risk factors like high blood pressure, diabetes, and high cholesterol in patients who had cancer treatments that put them at risk for heart problems, such as radiation to the heart area.
While we knew that these children are at risk for certain kinds of heart problems as they age, now we also know that adding in traditional cardiovascular risk factors increases their cardiovascular risks several fold. Their lifetime risk for heart problems and death from heart disease can be significantly reduced if appropriately managed.
What challenges remain in helping childhood cancer survivors?
We need to educate and train physicians and other health care providers to be experts in survivorship. We now have a fellowship here in pediatric survivorship offering specialized, in-depth training to people who want to have a career in taking care of survivors. It’s just now becoming available as a formal area of medical specialization.