Chronic health conditions among childhood cancer survivors decrease

Changes in treatment of pediatric cancer over recent decades have translated to a reduced risk of serious long-term late health effects of cancer therapy, according to the latest analysis from the Childhood Cancer Survivor Study, a National Cancer Institute funded resource for late-effects research, led by researchers at St. Jude Children's Research Hospital.

"This is the first comprehensive study to demonstrate how changes in treatments over time have impacted the occurrence of late effects experienced by childhood cancer survivors," said Todd Gibson, Ph.D., assistant member of the Department of Epidemiology and Cancer Control at St. Jude. "We found the 15-year cumulative incidence of people reporting at least one severe health condition decreased from 12.7 percent among childhood cancer survivors diagnosed in the 1970s to 10.1 percent for those diagnosed in the 1980s to 8.8 percent in the 1990s – a statistically significant decline."

Gibson will present the findings of the research at the American Society of Clinical Oncology annual meeting in Chicago on June 2.

This study used the CCSS data from 23,601 survivors to evaluate the incidence of severe, disabling/life-threatening or fatal chronic health conditions among five-year childhood cancer survivors diagnosed before their 21st birthday from 1970 through 1999. The median age of the survivors was 28 years. The study focused on the incidence of chronic illnesses in the first 15 years after diagnosis to provide an equal time frame for all participants regardless of when they were diagnosed.

Comparing survivors diagnosed in the 1970s to those diagnosed in the 1990s, the occurrence of severe health problems 15 years after initial diagnosis decreased significantly from:

• 13 percent to 5 percent among survivors of Wilms tumor (a rare kidney cancer)
• 18 percent to 11 percent among survivors of Hodgkin lymphoma
• 15 percent to 9percent among survivors of astrocytoma (the second most common childhood cancer)
• 10 percent to 6 percent among survivors of non-Hodgkin lymphoma
• 9 percent to 7 percent among survivors of acute lymphoblastic leukemia (the most common childhood cancer)

Decreases were largely driven by a reduced incidence of endocrine conditions (4.0 percent in the 1970s versus 1.6 percent in the 1990s) and subsequent cancers (2.4 percent in the 1970s versus 1.6 percent in the 1990s). Significant reductions were also found for gastrointestinal and neurological conditions, but not cardiac or pulmonary conditions.

"While we are glad to see these improvements," Gibson said, "a key point is that we have not identified any age or time since diagnosis when survivors no longer need to be concerned about their risk of treatment-related late health effects, as they seem to persist throughout their lifetime."