Sept. 8 (UPI) -- A study by St. Jude Children's Research Hospital found that childhood cancer survivors have double the risk for chronic conditions as the general population.
There are approximately 420,000 childhood cancer survivors in the United States, and that number is expected to grow as cure rates improve.
The research, published Thursday in The Lancet, was based on a statistical method known as cumulative burden to analyze the lifelong impact of 168 chronic health conditions on 5,522 St. Jude adult survivors of childhood cancer.
"Our primary objective is always to cure the cancer first," Dr. Nickhill Bhakta, an assistant member of the St. Jude Department of Global Pediatric Medicine, told UPI. "But there is a price to pay for a cure and the cure doesn't end the story."
The study was the first to assess and compare the cumulative burden of chronic disease in a group of childhood cancer survivors enrolled in the St. Jude Lifetime Cohort study, or St. Jude LIFE, and healthy volunteers matched for age and sex.
Researchers found that by age 50, the average pediatric cancer survivor had 17.1 chronic health conditions, including 4.7 that were considered severe or disabling, life-threatening or deadly, compared to the general population that averaged 9.2 chronic health conditions with 2.3 falling into the same categories.
"We are getting better at curing childhood cancer and improving overall outcomes," Bhakta said. "Over 80 percent of children now have a 10-year overall survival rate. However, the pediatric modalities we use come with a heavy price of chronic health conditions that present at age 20, 30 or 40 instead of 50, 60, 70 or 80. We're finding that a 30-year-old pediatric cancer survivor can have more severe chronic health conditions than a 60-year-old in the general population."
Bhakta explained that there are two different types of chronic conditions, those that develop early and persist throughout life, and others where the risk develops and increases over time.
"Each treatment has a different mechanism to affect health," Bhakta said. "Radiation in a child with a developing brain can stunt brain development leading to problems with higher executive functioning or developmental disabilities."
"For example, a class of chemotherapy drugs known as anthracyclines, are excellent at killing cancer, but can cause damage to the heart muscle, which persists throughout life, leading to an increased risk of heart attack or heart failure."
The goal of the study was to highlight these chronic conditions and the best methods for treatment in the clinical environment.
"We use the term survivor as a monolithic term, appropriately we want to celebrate when a child is cured of cancer," Bhakta said. "However, the population is not monolithic, we can't think of the survivors as monolithic in terms of chronic conditions."
Bhakta said that childhood cancer survivors with chronic conditions would benefit the most from integrated, specialized health care similar to what is being done "in other vulnerable populations like those with HIV or cerebral palsy. There's these clinics called medical homes with multiple practices to address multiple diseases."
Medical homes provide comprehensive, coordinated services to address patients' medical and psychosocial needs.
As doctors get better at treating pediatric cancer, researchers hope that they can find possible ways to lessen the long-term impacts of treatment options.
"We wanted to get a very big picture of what does the landscape of chronic health conditions look like," Bhakta said. "It has multiple ramifications on how we do things, it affects how we screen patients and how we treat patients who've already been cured. We are doing such a good job at treating pediatric cancers, we can now look at do we really need to use as much of these medicines and still get the same effect."