A St. Jude Children's Research Hospital study found that despite being diagnosed with life-threatening illnesses, childhood cancer patients are no more likely than their healthy peers to develop post-traumatic stress disorder (PTSD).

The research appears in the current online edition of the Journal of Clinical Oncology.

Young cancer patients were also more likely than children who experience other stressful events to report having benefited from the experience. Reported benefits included developing greater empathy and growing closer to family and friends.

The study included 255 St. Jude patients who were ages 8 to 17 when their cancer was diagnosed. Based on self-reported patient symptoms, researchers concluded that 2.8 percent, or seven patients, met the criteria for a diagnosis of PTSD either when the study was conducted or in the past. The PTSD was cancer-related in two patients. In the other five patients, the anxiety disorder was linked to a drive-by shooting, Hurricane Katrina or other stressful events.

This incidence of PTSD was comparable to rates reported in community samples of children without cancer and a similar group of 101 healthy peers recruited for the study. The prevalence, however, contrasts sharply with previous reports from other investigators who identified cancer-related PTSD as a widespread problem. Those estimates suggested that 20 to 35 percent of childhood cancer patients would develop PTSD.

"These results should be very reassuring to childhood cancer patients and their families," said the study's first and corresponding author Sean Phipps, Ph.D., St. Jude Department of Psychology chair. "A cancer diagnosis is a highly significant and challenging event, but this study highlights the impressive capacity of children to adjust to changes in their lives and in most cases do just fine or even thrive emotionally as a result."

PTSD is a treatable anxiety disorder that can develop following combat, natural disasters, assaults, life-threatening illnesses and other terrifying events that result in real or potential physical harm. The diagnosis is based on patient reports of certain symptoms, including persistent frightening thoughts, flashbacks, numbness, detachment and sleep disturbances.

For this study, researchers used three established methods to screen paediatric cancer patients and their healthy peers for PTSD. Those included a symptom check list and a structured diagnostic interview about the event each child identified as the most traumatic. Parents were also interviewed about PTSD symptoms in themselves and their children. The study is part of a long-term project to track adjustment and predictors of adjustment in paediatric cancer patients.

Unlike many previous studies of PTSD in cancer patients, researchers initially refrained from asking patients specifically about their diagnosis. Investigators wanted to avoid suggesting to patients that their cancer diagnoses were traumatic, Phipps explained. "We know such suggestions, called focusing illusions, prime individuals to think about their cancer experience as traumatic and leaves them prone to exaggerating its impact in subjective reports," he said.

More than half of the patients identified their cancer as the most stressful event they had experienced. Of those who were long-term survivors, however, less than 25 percent cited cancer as their most traumatic experience. The study included patients whose cancer had been diagnosed between 1 month and more than 5 years earlier.

The cancer patients were recruited between 2009 and 2012 and were battling cancers of the blood, brain and other organs. The patients were divided into roughly equal groups based on the time since their diagnosis. Unlike previous studies of PTSD in paediatric cancer patients, this study included a similar group of healthy children recruited from Memphis-area schools.

Parental interviews suggested slightly higher rates of PTSD in both cancer patients and their healthy peers. Based on parent-reported symptoms, researchers reported that 5.9 percent met the criteria for PTSD. Two percent of the non-cancer volunteers also met the criteria. The difference between the two groups was not statistically significant.

The study involved St. Jude patients, but Phipps said the findings should apply to children treated at other institutions.

The other authors of this study are James Klosky, Alanna Long, Melissa Hudson, Qinlei Huang and Hui Zhang, all of St. Jude; and Robert Noll of the University of Pittsburgh Medical Center.

The study was funded in part by a grant (CA136782) from the National Institutes of Health and ALSAC.

Source: JCO