The number of childhood cancer survivors in the U.S. has increased, but the majority of those who have survived five or more years after diagnosis face chronic health problems related to their treatment, according to a new Northwestern Medicine study in collaboration with the National Cancer Institute (NCI) and St. Jude Children's Research Hospital.

The study is the first to estimate the prevalence of treatment-related chronic disease among survivors of childhood cancer at a national level. It found there are nearly 400,000 childhood cancer survivors in the U.S. as of 2011, up 60,000 from 2005.

"We've been able to increase the number of survivors of paediatric cancer, but simply curing their disease isn't enough," said lead author Siobhan Phillips, assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine. "We need a more coordinated approach to their care to help prevent or delay some of these chronic health problems that affect the quality of their lives. We want them to thrive, not simply survive."

The study was published April 1 in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

"The magnitude of diseases at relatively young ages is quite striking, since you would not expect many of these diseases to be a problem in the general population until much older ages," said Phillips, also a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.

Among the health problems experienced by childhood cancer survivors are mental impairment, anxiety, pain and physical limitations that affect daily living.

About 70 percent of the survivors of childhood cancers were estimated to have a mild or moderate chronic condition, and about 32 percent were estimated to have a severe, disabling, or life-threatening chronic condition.

An estimated 35 percent of the survivors, ages 20 to 49, had neurocognitive dysfunction; about 13 to 17 percent of those in this age group had self-reported functional impairment, activity limitations, impaired mental health, pain or anxiety/fear.

"These facts should challenge all of us in the field not to be content simply with improving life span, but to dedicate the future of this field to improving the 'health span' of our survivors," said Dr. Greg Armstrong, principal investigator of the Childhood Cancer Survivor Study and a paediatrician at St. Jude.

"Several important research questions arise from these findings as we consider how to increase our understanding of the chronic and late effects of treatment and how to best develop guidelines and interventions to treat these chronic morbidities in this important population," said co-author Lynne Padgett, rehabilitation psychologist and program director of the NCI at the National Institutes of Health (NIH).

Childhood cancer survivors should have health care providers who are knowledgeable about their increased risk of chronic health problems, Phillips said.

Northwestern's Lurie Cancer Center has a comprehensive long-term follow-up program for adult survivors of paediatric cancer. The STAR Program follows survivors through adulthood, focusing on their special medical and psychological needs.

Source - Eurekalert