Cancer Progress and Priorities: Childhood Cancer

Abstract

Background:: It is estimated that 300,000 children 0-14 years of age are diagnosed with cancer worldwide each year. While the absolute risk of cancer in children is low, in high-income countries, it is the leading cause of death due to disease in children. In spite of this, the etiologies of childhood cancer are largely unknown.

Methods:: We reviewed the literature on several components of the epidemiology of childhood cancer, including incidence, survival, risk factors, etiologic heterogeneity, and prevention. After describing known patterns in the epidemiology of childhood cancer, we propose future directions for epidemiologic research.

Results:: Recent studies indicate the worldwide incidence of childhood cancer is underestimated, especially in middle- and low-income countries. While survival continues to improve, there are significant disparities across the globe. In terms of risk factors, there are a few well-established associations including race/ethnicity, birthweight, birth defects, and ionizing radiation. Identifying novel risk factors is imperative for future prevention efforts.

Conclusions:: Future epidemiologic studies of childhood cancer should incorporate novel exposure methodologies, molecular features of tumors, and a more complete assessment of gene-environment interactions.

Impact:: It is hoped that our understanding of the causes of childhood cancer can be better ascertained, leading to novel surveillance or prevention strategies.

Figure 1.

Worldwide estimated age-standardized incidence for (a) all childhood cancer and (b) leukemia in 2018

Figure 2.

Distribution of tumors across the pediatric age spectrum

Figure 3.

Improvements in 5-year survival for childhood cancer, SEER, 1975-2010

Figure 4.

Genes and variants identified in GWAS of childhood cancer; up to 5 of the top SNPs with p < 10-8 in the GWAS catalogue (https://www.ebi.ac.uk/gwas/home) are displayed, with information for recent GWAS of T-cell ALL and LCH added.