By Kathleen Raven
NEW YORK (Reuters Health) - People who had cancer as children are more likely to be treated for neurodevelopmental, emotional or behavioral disorders later in life, a new Danish study finds.
Researchers examined records from survivors' siblings as well, finding those who were younger than 10 years old or not yet born when the cancer was diagnosed tended to also have higher risks of mental trouble later on.
Programs designed especially for sibling mental health are quite rare, said lead author Dr. Lasse Lund of the Cancer Society Research Centre and University of Copenhagen. Parents should "keep an eye on siblings as well," he said.
His team's study included 7,085 Danish children treated for cancer between 1975 and 2010 and 13,105 of their siblings. The researchers used psychiatric registry data to track hospital visits during the same time period.
In total, 494 survivors of childhood cancer had at least one inpatient or outpatient visit for a mental health disorder, as did 1,066 siblings.
Compared to people of the same age without cancer, male survivors of central nervous system tumors, blood cancers such as leukemia and solid tumors had a 50 percent increased risk of mental health-related hospital visits and inpatient stays. Girls and women with a history of childhood cancer had a 26 percent increased risk.
Lund said because males in the general population report fewer mental disorders than females, the difference in risk estimates between genders is not as large as it looks.
Children diagnosed with cancer before age 10 had the highest risk of going on to be treated for a mental disorder, the researchers found, and male survivors in particular were at an increased risk of depression.
Siblings who were 15 years old or older at the time of diagnosis had a reduced risk of mental disorders compared to the general population, according to findings published in The Lancet Oncology.
"We're not quite sure what happens there," Lund said. "Perhaps they appreciate life more, and they do not take little things seriously because they have experienced the possibility of death."
Although cancer kills more U.S. children than any other disease, the proportion of young patients who survive at least five years after diagnosis has improved from less than half before the 1970s to about 80 percent.
A past Danish study found an increased risk of mental problems associated only with central nervous system cancers - which include the brain tumors known as gliomas and medulloblastomas - but this study is larger and more thorough, Lund said.
"Our hope is that by discovering and reacting to the mental disorders early, we can treat them earlier and better," he told Reuters Health.
For years, researchers have suspected a relationship between chemotherapy treatments and later psychotic disorders, such as schizophrenia and bipolar disorder.
"The easiest way would be to remove the drug culprit, but it's not that simple," Lund said. He added that the risk of mental disorders comes also from "the trauma and isolation, which are things we cannot do much about."
Some schools in Denmark have created ambassador programs designed to help improve the long-term mental health of children with cancer. These ambassadors are charged with visiting the patient in the hospital once a week during the school year, Lund said.
"Certainly survivors need to be followed for mental disorders," said Dr. Lillian Meacham of Emory University's Winship Cancer Institute in Atlanta. Meacham, a pediatric endocrinologist who was not involved in the current study, said hospital survivor programs should keep a psychologist embedded on staff.
"Having access to a psychologist is important," she told Reuters Health.
"We know that childhood cancer survivors deal with psychosocial effects later in life, like anxiety and depression," said Karen Kinahan, a clinical nurse specialist at Northwestern University's Robert H. Lurie Comprehensive Cancer Center in Chicago.
"I was surprised to find that hospital contacts for anxiety were relatively low among male and female survivors," Kinahan, who did not work on the new research, told Reuters Health.
Still, she said the study reinforces the importance of psychological attention for young cancer patients.
"The more we learn, the more we can improve our care," she said.
SOURCE: bit.ly/1aOQGr1 The Lancet Oncology, online August 14, 2013.