Introduction
Pediatric cancer rates have increased over the past four decades; in 2022, an estimated 15,950 U.S. youth were diagnosed with cancer [1]. Fortunately, treatment advances have increased survival rates, with 85% of children surviving > 5 years after diagnosis [1]. The growing incidence and survival rates highlight the need to improve psychosocial outcomes among pediatric cancer populations.
Pediatric cancer patients, survivors, and their family members report significant psychosocial stress related to fear of dying, long hospital stays, medical procedures, and loss of control [2]. Alarmingly, up to 82% of young survivors report posttraumatic stress symptoms (PTSS), which often include involuntary recurrent memories or nightmares, emotional numbing, and heightened physiological arousal [3–5]. Cancer-related PTSS have been associated with functional and structural alterations in the developing brain, particularly in fear-related neurocircuitry [5,6], and predicting long-term adjustment [7].
Emerging data indicate that mindfulness, breathing, and meditation practices are promising for relieving pain and emotional distress in pediatric cancer populations [8,9]. Our group demonstrated that a 60-minute mindfulness-oriented martial-arts therapy (MAT) session is associated with reductions in these symptoms in children with cancer and survivors [10,11].
Recent research has demonstrated that mindfulness and MAT are associated with functional changes in stress-sensitive brain regions, including the hippocampus [12], which is involved in stress regulation, learning, emotional memory, and susceptibility to PTSS. Particularly, reduced volume of the left hippocampus is frequently associated with more severe PTSS [13,14] and predicts posttraumatic stress disorder development [15]. Moreover, smaller hippocampal volumes at baseline have been related to greater reductions in PTSS in adults following an intervention [16].
Although MAT has been shown to acutely reduce emotional distress in pediatric cancer patients and survivors [11], less is known about effects following multiple sessions on PTSS. Further, while studies in adults suggest that hippocampal volume may be a biomarker of PTSS severity and of intervention response, no studies have examined these neurobiological correlates in pediatric cancer populations. Our pilot study aimed to examine the effects of a four-week MAT on cancer-related PTSS in children with cancer and survivors. Baseline neuroimaging scans were performed to evaluate whether hippocampal volumes were associated with baseline PTSS or change in PTSS from baseline to post-intervention.