Health gap between childhood cancer survivors and siblings widens with age
Adult survivors of childhood cancer face significant health problems as they age and are five times more likely than their siblings to develop new cancers, along with heart and other serious health conditions beyond age 35 years, according to the latest findings from the world's largest study of childhood cancer survivors.
The federally funded Childhood Cancer Survivor Study (CCSS), led by St. Jude Children's Research Hospital in Memphis, Tennessee, found that the health gap between survivors and their siblings widens with age. Survivors who were 20 to 34 years old were 3.8 times more likely than siblings of the same age to have experienced severe, disabling, life-threatening, or fatal health conditions. By age 35 years and beyond, however, survivors were at five-fold greater risk. The study was published in the Journal of Clinical Oncology (2014; doi:10.1200/JCO.2013.51.1055).
By age 50 years, more than half of childhood cancer survivors had experienced a life-altering health problem, compared with less than 20% of same-aged siblings. More than 22% of survivors had at least two serious health problems and about 10% reported three or more. The problems included new cancers as well as diseases of the heart, lungs, liver, kidneys, and hormones.
"Survivors remain at risk for serious health problems into their 40s and 50s, decades after they have completed treatment for childhood cancer," said first and corresponding author Gregory Armstrong, MD, of St. Jude. "In fact, for survivors, the risk of illness and death increases significantly beyond the age of 35 [years]. Their siblings don't share these same risks."
Among survivors who reached age 35 years without serious health problems, 25.9% developed a significant health problem in the next decade. In comparison, 6% of siblings developed their first serious health condition between age 35 years and 45 years.
The study involved 14,359 adult survivors who were treated for a variety of pediatric cancers at one of 26 US and Canadian medical centers. The research also included 4,301 siblings. For this study, CCSS investigators focused on 5,604 survivors who have now aged beyond 35 years. The results provide the broadest snapshot yet of how the first generation of childhood cancer survivors is faring as they age. The oldest survivors in this study were in their 50s.
The findings highlight the importance of lifelong, risk-based health care for childhood cancer survivors, Armstrong said. Depending on their cancer treatment and other risk factors, follow-up care may include mammography and other health checks at a younger age than is recommended for the general public.
The study also adds to evidence that some survivors experience accelerated aging, possibly due to their cancer treatment. Researchers are still trying to identify the cause. In this study, 24-year-old childhood cancer survivors and their 50-year-old siblings reported similar rates of severe, life-threatening, or fatal health problems.