Polygenic Risk and Chemotherapy-Related Subsequent Malignancies in Childhood Cancer Survivors: A Childhood Cancer Survivor Study and St Jude Lifetime Cohort Study Report

Genetic and epigenetic bases of long-term adverse effects of childhood cancer therapy

Over the past decade, genome-scale molecular profiling of large childhood cancer survivorship cohorts has led to unprecedented advances in our understanding of the genetic and epigenetic bases of therapy-related adverse health outcomes in this vulnerable population. To facilitate the integration of knowledge generated from these studies into formulating next-generation precision care for survivors of childhood cancer, we summarize key findings of genetic and epigenetic association studies of long-term therapy-related adverse effects including subsequent neoplasms and cardiomyopathies among others. We also discuss therapy-related genotoxicities including clonal haematopoiesis and DNA methylation, which may underlie accelerated molecular ageing. Finally, we highlight enhanced risk prediction models for survivors of childhood cancer that incorporate both genetic factors and treatment exposures, aiming to achieve enhanced accuracy in predicting risks for this population. These new insights will hopefully inspire future studies that harness both expanding omics resources and evolving data science methodology to accelerate the translation of precision medicine for survivors of childhood cancer.

Cancer mortality in children surviving congenital heart interventions: A study from the Pediatric Cardiac Care Consortium

INTRODUCTION

Children with congenital heart defects (CHD) have shorter life expectancy than the general population. Previous studies also suggest that patients with CHD have higher risk of cancer. This study aims to describe cancer-related mortality among patients with a history of CHD interventions using the Pediatric Cardiac Care Consortium (PCCC), a large US cohort of such patients.

METHODS

We performed a retrospective cohort study of individuals (<21 years) who underwent interventions for CHD in the PCCC from 1982 to 2003. Patients surviving their first intervention were linked to the National Death Index through 2020. Multivariable models assessed risk of cancer-related death, adjusting for age, sex, race, and ethnicity. Patients with/without genetic abnormalities (mostly Down syndrome [DS]) were considered separately, due to expected differential risk in cancer.

RESULTS

Among the 57,601 eligible patients in this study, cancer was the underlying or contributing cause of death for 208; with 20% among those with DS. Significantly increased risk of cancer-related death was apparent among patients with DS compared to the non-genetic group (aHR: 3.63, 95% confidence interval [CI]: 2.52-5.24, p < .001). For the group with non-genetic abnormalities, the highest association with cancer-related death compared to those with mild CHD was found among those with more severe CHD (severe two-ventricle aHR: 1.82, 95% CI: 1.04-3.20, p = .036, single-ventricle aHR: 4.68, 95% CI: 2.77-7.91, p < .001).

CONCLUSIONS

Patients with more severe forms of CHD are at increased risk for cancer-related death. Despite our findings, we are unable to distinguish whether having CHD raises the risk of cancer or reduces survival.

Radiation Therapy Technology Advances and Mitigation of Subsequent Neoplasms in Childhood Cancer Survivors

PURPOSE

In this Pediatric Normal Tissue Effects in the Clinic (PENTEC) vision paper, challenges and opportunities in the assessment of subsequent neoplasms (SNs) from radiation therapy (RT) are presented and discussed in the context of technology advancement.

METHODS AND MATERIALS

The paper discusses the current knowledge of SN risks associated with historic, contemporary, and future RT technologies. Opportunities for research and SN mitigation strategies in pediatric patients with cancer are reviewed.

RESULTS

Present experience with radiation carcinogenesis is from populations exposed during widely different scenarios. Knowledge gaps exist within clinical cohorts and follow-up; dose-response and volume effects; dose-rate and fractionation effects; radiation quality and proton/particle therapy; age considerations; susceptibility of specific tissues; and risks related to genetic predisposition. The biological mechanisms associated with local and patient-level risks are largely unknown.

CONCLUSIONS

Future cancer care is expected to involve several available RT technologies, necessitating evidence and strategies to assess the performance of competing treatments. It is essential to maximize the utilization of existing follow-up while planning for prospective data collection, including standardized registration of individual treatment information with linkage across patient databases.

Survival difference between secondary and de novo acute myeloid leukemia by age, antecedent cancer types, and chemotherapy receipt

BACKGROUND

This study compared the survival of persons with secondary acute myeloid leukemia (sAML) to those with de novo AML (dnAML) by age at AML diagnosis, chemotherapy receipt, and cancer type preceding sAML diagnosis.

METHODS

Data from Surveillance, Epidemiology, and End Results 17 Registries were used, which included 47,704 individuals diagnosed with AML between 2001 and 2018. Multivariable Cox proportional hazards regression was used to compare AML-specific survival between sAML and dnAML. Trends in 5-year age-standardized relative survival were examined via the Joinpoint survival model.

RESULTS

Overall, individuals with sAML had an 8% higher risk of dying from AML (hazard ratio [HR], 1.08; 95% confidence interval [CI], 1.05-1.11) compared to those with dnAML. Disparities widened with younger age at diagnosis, particularly in those who received chemotherapy for AML (HR, 1.14; 95% CI, 1.10-1.19). In persons aged 20-64 years and who received chemotherapy, HRs were greatest for those with antecedent myelodysplastic syndrome (HR, 2.04; 95% CI, 1.83-2.28), ovarian cancer (HR, 1.91; 95% CI, 1.19-3.08), head and neck cancer (HR, 1.55; 95% CI, 1.02-2.36), leukemia (HR, 1.45; 95% CI, 1.12-1.89), and non-Hodgkin lymphoma (HR, 1.42; 95% CI, 1.20-1.69). Among those aged ≥65 years and who received chemotherapy, HRs were highest for those with antecedent cervical cancer (HR, 2.42; 95% CI, 1.15-5.10) and myelodysplastic syndrome (HR, 1.28; 95% CI, 1.19-1.38). The 5-year relative survival improved 0.3% per year for sAML slower than 0.86% per year for dnAML. Consequently, the survival gap widened from 7.2% (95% CI, 5.4%-9.0%) during the period 2001-2003 to 14.3% (95% CI, 12.8%-15.8%) during the period 2012-2014.

CONCLUSIONS

Significant survival disparities exist between sAML and dnAML on the basis of age at diagnosis, chemotherapy receipt, and antecedent cancer, which highlights opportunities to improve outcomes among those diagnosed with sAML.

Polygenic risk scores, radiation treatment exposures and subsequent cancer risk in childhood cancer survivors

Survivors of childhood cancer are at increased risk for subsequent cancers attributable to the late effects of radiotherapy and other treatment exposures; thus, further understanding of the impact of genetic predisposition on risk is needed. Combining genotype data for 11,220 5-year survivors from the Childhood Cancer Survivor Study and the St Jude Lifetime Cohort, we found that cancer-specific polygenic risk scores (PRSs) derived from general population, genome-wide association study, cancer loci identified survivors of European ancestry at increased risk of subsequent basal cell carcinoma (odds ratio per s.d. of the PRS: OR = 1.37, 95% confidence interval (CI) = 1.29-1.46), female breast cancer (OR = 1.42, 95% CI = 1.27-1.58), thyroid cancer (OR = 1.48, 95% CI = 1.31-1.67), squamous cell carcinoma (OR = 1.20, 95% CI = 1.00-1.44) and melanoma (OR = 1.60, 95% CI = 1.31-1.96); however, the association for colorectal cancer was not significant (OR = 1.19, 95% CI = 0.94-1.52). An investigation of joint associations between PRSs and radiotherapy found more than additive increased risks of basal cell carcinoma, and breast and thyroid cancers. For survivors with radiotherapy exposure, the cumulative incidence of subsequent cancer by age 50 years was increased for those with high versus low PRS. These findings suggest a degree of shared genetic etiology for these malignancy types in the general population and survivors, which remains evident in the context of strong radiotherapy-related risk.