Cancer incidence and type of treatment hospital among children, adolescents, and young adults in Japan, 2016-2018

Abstract

Cancer in children, adolescents, and young adults (AYAs) although rare, is the leading disease-specific cause of death in Japan. This study aims to investigate cancer incidence and type of treatment hospital among children and AYAs in Japan. Cancer incidence data (2016-2018) for those aged 0-39 years were obtained from the Japanese population-based National Cancer Registry. Cancer types were classified according to the 2017 update of the International Classification of Childhood Cancer (Third Edition), and AYA Site Recode 2020 Revision. Cases were also categorized into three groups: those treated at core hospitals for pediatric cancer treatment (pediatric cancer hospitals [PCHs]), those treated at designated cancer care hospitals, and those treated at nondesignated hospitals. The age-standardized incidence rate was 166.6 (per million-person years) for children (age 0-14 years) and 579.0 for AYAs (age 15-39 years) (including all cancers and benign or uncertain-behavior central nervous system [CNS] tumors). The type of cancer varied with age: hematological malignancies, blastomas, and CNS tumors were common in children under 10 years, malignant bone tumors and soft tissue sarcomas were relatively common in teenagers, and in young adults over 20 years, carcinomas in thyroid, testis, gastrointestinal, female cervix, and breast were common. The proportion of cases treated at PCHs ranged from 20% to 30% for children, 10% or less for AYAs, and differed according to age group and cancer type. Based on this information, the optimal system of cancer care should be discussed.

Keywords: adolescent and young adult oncology; cancer registration; childhood cancer; epidemiology; incidence.

FIGURE 1

Proportional distribution of cancer type by age group, age 0–39 years, 2016–2018, Japan. Cancers were classified by the International Classification of Childhood Cancer, volume 3, updated 2017. Source: Japanese population‐based National Cancer Registry. CNS, central nervous system.

FIGURE 2

Age‐specific incidence rates by cancer type, age 0–39 years, 2016–2018, Japan. Cancers were classified by the International Classification of Childhood Cancer, volume 3, updated 2017. Classifications XI. Other malignant epithelial neoplasms and malignant melanomas and XII. Other and unspecified malignant neoplasms were excluded. Source: Japanese population‐based National Cancer Registry. CNS, central nervous system.

FIGURE 3

Proportional distribution of cancer type by age group and sex, age 15–39 years, 2016–2018, Japan. Cancers were classified by adolescent and young adult (AYA) Site Recode 2020 Revision. Source: Japanese population‐based National Cancer Registry. CNS, central nervous system.