According to a new Swedish study, people who survive cancer during childhood have an increased risk of developing an autoimmune disease as they grow older.
But first, what is autoimmune disease? The function of your body’s immune system is to guard against infection and disease, using the white cells to attack what it perceives to be invaders, such as viruses, toxins, and cancer cells. The immune system uses special proteins called antibodies to target and then neutralize these invaders. If you have an autoimmune disease, your immune system malfunctions and attacks beneficial cells in your body instead, essentially turning on itself. The proteins involved in this process are called “autoantibodies,” somehow programmed to target healthy cells instead of pathogens such as cancer. The reasons behind this type of condition are not yet fully understood. There are 80+ different types of autoimmune disease, with some of the most common being Type 1 diabetes, multiple sclerosis, rheumatoid arthritis, and celiac disease.
In a recent study, Dr. Anna Sallfors Holmqvist from Skane University Hospital, Lund University, Sweden, and her research team evaluated data for 20,361 patients from Iceland, Sweden and Denmark, taken from registry information from the 1940s and 50s through to the end of 2008. These patients had to have been diagnosed with cancer between birth and age 19 and have survived at least one year following the initial diagnosis. Researchers also compared these results to those of 125,794 subjects of the same sex, age and country of residence who did not have cancer in the same age range. The researchers followed participants for an average of 15–19 years.
The result? The team discovered that childhood cancer survivors had a 40% increased risk of developing autoimmune diseases. The autoimmune diseases that seemed to occur most often in these study subjects were autoimmune hemolytic anemia, Addison’s disease, and polyarteritis nodosa. Other diseases that surviving cancer patients were more prone to included pernicious anemia, sarcoidosis, rheumatic heart disease, scleroderma, idiopathic thrombocytopenic purpura, diabetes, Sjogren’s syndrome and Hashimoto’s thyroiditis.
The researchers also discovered that patients diagnosed with Hodgkin’s lymphoma, kidney tumors, central nervous system neoplasms, and leukemia were 40% to 60% more likely to develop an autoimmune disorder later in life than those who didn’t have cancer during childhood.
Why does this happen to childhood cancer survivors? According to the study, which was published online in Annals of the Rheumatic Diseases, both the cancer and the treatment for it (often chemotherapy or radiation) have an impact on a person’s immune system, especially a child’s. Also, because the immune system is so affected by the disease and its treatment, cancer patients are often more prone to infections, further altering their immune function. Specifically, the researchers say that, alone or combined, the factors of childhood cancer, cancer treatment, and resulting infections can lead to the development of autoantibodies, which can cause various autoimmune diseases.
According to the study’s research team, all of this means that survivors of childhood cancer need to be monitored closely for autoimmune diseases as they grow older and take what health precautions they can to prevent them. “Cure is no longer a sufficient goal in childhood cancer care,” said Dr. Sallfors Holmqvist, “As the vast majority of these patients survive, attention must be paid to their long-term quality of life and health challenges.”
Sources for Today’s Article:
Sallfors Holmqvist, A., MD, et al., “Autoimmune diseases in Adult Life after Childhood Cancer in Scandinavia (ALiCCS),” Annals of the Rheumatic Diseases, November 10, 2015; http://ard.bmj.com/content/early/2015/10/08/annrheumdis-2015-207659.full.
“Autoimmune Diseases,” MedlinePlus; https://www.nlm.nih.gov/medlineplus/autoimmunediseases.html, last accessed November 13, 2015.
“Autoimmune disorders,” MedlinePlus; https://www.nlm.nih.gov/medlineplus/ency/article/000816.htm, last accessed November 13, 2015.
Garcia, J. “Pediatric Cancer Survivors at High Risk for Autoimmune Disease,” Medicine Net web site; November 11, 2015, http://www.medscape.com/viewarticle/854285.