ABSTRACT More than 70% of children and adolescents diagnosed with a bone sarcoma now survive at least five years post- diagnosis. Unfortunately, curative treatments result in toxicities that leave many survivors with a substantial burden of adverse physical and mental health outcomes, including chronic pain. Up to 59% of long-term survivors report pain, and bone sarcoma survivors are 4 times as likely to report pain with daily interference compared to other survivors and have increased opioid use and markers for misuse. Relevant to this application, Black and Hispanic survivors disproportionately experience pain during survivorship. We suspect this disparity may be explained, in part, by social determinants of health (SDOH), which also contribute to disparities in the general population. Despite the high prevalence and burden of pain among Black and Hispanic childhood cancer survivors, non-pharmacologic interventions tailored for this population are lacking. Cognitive behavioral therapy (CBT) is an established non-pharmacologic treatment for chronic pain that focuses on addressing maladaptive thoughts and behaviors related to pain, and when combined with transcranial direct current stimulation (tDCS) of brain regions responsible for cognitive and affective processing of pain may enhance chronic pain control in cancer survivors. The recent development of mobile CBT programs and remote delivery of tDCS has reduced barriers to access care. However, these programs have not been adapted to be culturally responsive to underserved populations thus limiting their reach, utility, and uptake. We propose to culturally tailor an established, evidence-based mobile CBT program for chronic pain to Black and Hispanic adolescent survivors. Once the program is fully adapted, we propose to pair the culturally adapted mobile CBT with remotely delivered tDCS in a racially/ethnically diverse sample of non-Hispanic White, non-Hispanic Black, and Hispanic adolescent survivors of pediatric bone sarcoma. Further, we propose to examine the impact of patient-reported comorbidities (e.g., depression, anxiety, sleep) and SDOHs (e.g., area deprivation index, parent SES) on intervention outcomes. Importantly, non-pharmacological interventions delivered during adolescence and early survivorship are critical to modify a trajectory of chronic pain and negative outcomes into adulthood. Positive results from this study will be used for a future Phase 3 implementation trial to demonstrate generalizability and scalability to the large and geographically diverse population of all childhood cancer survivors with chronic pain.

NARRATIVE This study will evaluate the impact of culturally adapted mobile cognitive behavioral therapy and transcranial direct current stimulation on pain intensity and functional disability in a racially/ethnically and geographically diverse sample of adolescent survivors of bone sarcoma with chronic pain. Results will inform standard of care for survivors of childhood cancer, as few efficacious, non-pharmacologic interventions are available and accessible, particularly for underserved survivors.