Childhood cancer survivors are at increased risk for several autoimmune disorders, according to research published in the Annals of Rheumatic Diseases.
Over the past few decades, survival after childhood cancer has improved dramatically, resulting in an 80% 5-year survival rate among children treated for cancer in Nordic countries. However, this population is at risk for numerous health problems, and this risk can increase with age.
“Within the spectrum of autoimmune diseases, the most prominent excesses occurring after childhood cancer are confined to already known late effects, such as insulin-dependent diabetes mellitus and other endocrine disorders,” the authors wrote. “Nevertheless, increased risks were also seen for a wide range of relatively rare autoimmune diseases after treatment for several types of childhood malignancies.”
Researchers identified 20,361 participants who survived cancer for more than 1 year and who were diagnosed before the age of 20. They also identified 125,794 participants without a cancer diagnosis for the comparison group.
The participants were identified using national cancer registry data from Denmark, Iceland, and Sweden between the 1940s and 2008. The investigators followed the participants for an average of 15 to 19 years and used hospital records to calculate standardized hospitalization rate ratios (SHRRs) and absolute excess risks (AERs) for both groups.
The results showed that, when compared to all autoimmune diseases, childhood cancer survivors had an increased SHRR of 1.4 (95% confidence interval [CI], 1.3-1.5) and a corresponding AER of 67 per 100,000 person-years.
SHRRs were higher for 11 out of 33 autoimmune diseases examined in the study. The researchers found that autoimmune hemolytic anemia was 17 times more likely among childhood cancer survivors, Addison’s disease was 14 times more likely, and polyarteritis nodosa was 6 times more likely. Other autoimmune diseases that were more likely to occur in survivors of cancer in childhood included chronic rheumatic heart disease, localized scleroderma, and insulin-dependent diabetes.
Overall, 724 (3.6%) of the childhood cancer survivors had at least 1 episode of hospital contact related to an autoimmune condition, which is 40% higher than the expected risk for hospitalization.
“Cure is no longer a sufficient goal in childhood cancer care,” the authors concluded. “As the vast majority of these patients survive, attention must be paid to their long-term quality of life and health challenges. The results of this large, retrospective study fill some gaps in the knowledge about the risks for autoimmune diseases after treatment for childhood cancer.”
Holmqvist AS, Olsen JH, Mellemkjaer L, et al. Autoimmune diseases in adult life after childhood cancer in Scandinavia (ALiCCS). Ann Rheum Dis. 2015; doi: 10.1136/annrheumdis-2015-207659.