1 | INTRODUCTION
Remarkable progress in the overall survival of children with cancer over the past several decades emphasizes the importance of long-term follow-up care for survivors.1 Indeed, the late effects of treatment, from secondary malignancies to cardiovascular disease, affect every major organ system and demonstrate significant heterogeneity in incidence based on underlying malignancy and specific exposures.2 Clinical guidelines offer a framework for disease surveillance after cancer treatment, yet lack of follow-up is a significant barrier to early detection of late effects. The electronic health record (EHR) sparks unique approaches to construct, maintain, and leverage childhood cancer survivorship cohorts to optimize health care delivery and as a platform for survivorship research. Ascertainment of treatment exposures aids in risk stratification and identification of survivors lost to follow-up.
Risk stratification of patients to determine appropriate levels of follow-up care, both for the coordination with primary care providers as well as the identification of high-risk survivors who would benefit from regular subspecialist visits, facilitates judicious use of health care resources to optimize patient outcomes.3 In the United Kingdom, different levels of follow-up care were proposed based on treatment exposures4 were later validated to ensure appropriate capture of adverse effects.5 The British Childhood Cancer Survivor Study (BCCSS) further refined the risk stratification through the integration of underlying malignancy.6 The introduction of novel targeted agents and immunotherapy underscores the need for an adaptable system to incorporate new risks for late effects from treatment. Albeit an emerging field, there are associated cardiac,7renal,8 and endocrinologic9 adverse effects during and shortly after treatment with these therapeutic agents.10 In the coming years, new late effects from these modalities will likely impact the care of adult survivors of childhood cancer.
As knowledge of late effects risk improves, guideline recommendations offer a framework for disease surveillance in order to mitigate further complications. The Children’s Oncology Group (COG) regularly updates long-term follow-up guidelines based on treatment exposure, including radiation, surgery, immunotherapy, and each specific chemotherapeutic agent.11 Furthermore, international efforts to harmonize different recommendations across the globe provide another layer for evidence-based survivorship care.12 Over the past decade, published recommendations for cardiomyopathy,13 breast cancer,14fertility,15,16, thyroid cancer,17and ototoxicity18 address major challenges for survivors and inform delivery of appropriate care for early detection of these late effects. Large, multi-institutional longitudinal studies, such as the Childhood Cancer Survivorship Study (CCSS),19offer a wealth of data to inform validated risk prediction models for acute ovarian failure,20thyroid cancer,21 and cardiovascular outcomes.22,23 Translation and implementation of these recommendations and models into clinical practice, on an individual patient and population health level, represent a tremendous opportunity to optimize health outcomes in the digital age.
Long-term follow-up care of survivors enhances patient education and early detection of late effects.24 Predictors of suboptimal follow-up, such as age, insurance status, and race/ethnicity, help identity at-risk populations.25 Studies of adult cancer patients from rural areas reveal significant disparities with regards to overall mortality26-28 and financial toxicity29; however, there is a paucity of data for survivors of childhood cancer. During active treatment, distance to the cancer center is a considerable barrier,30,31especially for adolescents and young adults.32 For high-risk survivors, distance to a comprehensive cancer center may also influence their likelihood of receiving appropriate follow-up care.
The primary aim of this study was to harness an institutional cancer registry, which follows the standards of and reports to the National Cancer Database (NCDB),33 to construct a childhood cancer survivorship cohort, integrate EHR and geospatial data to analyze follow-up care patterns, and determine factors associated with inadequate follow-up care. Risk stratification of survivors provides an additional lens to prioritize survivors at risk for inadequate follow-up care.