Trends in cancer incidence and mortality of children, adolescents, and young adults in Hong Kong, 2003-2023: Comparison with East Asia, US, UK, and Australia.

Abstract

e22614 Background: Although survival of cancers in childhood, adolescence and young adulthood (CAYA) has improved globally, incidence and mortality data remain limited in Hong Kong. This study aims to compare long-term trends of CAYA cancer in Hong Kong with East Asian and high-income Western countries to inform regional cancer burden and survivorship strategies. Methods: All cancers except non-melanoma skin cancer were analyzed among individuals aged 0–39 years. Cancer incidence and mortality in Hong Kong (2003-2023) were obtained from the population-based Hong Kong Cancer Registry. Incidences for mainland China, Japan, Korea, the US, UK and Australia were extracted from GLOBOCAN 2022 and CI5 plus (2003-2017), while mortality data were derived from the Global Burden of Disease Study (2003-2023). Age-standardized incidence rates (ASIRs, per 100,000) and mortality rates (ASMRs, per 100,000) were calculated using Segi’s world standard population. Temporal trends were assessed by average annual percentage changes (AAPCs) using Joinpoint regression. Results: In 2022, ASIR of CAYA cancer in Hong Kong (34.43) was lower than Australia (49.1), US (44.5), Korea (41.7), UK (38.2) and mainland China (34.8), but higher than Japan (31.6). Hong Kong had the lowest ASMR (4.12) among mainland China (8.38), Korea (5.16), US (5.0), Japan (4.68), UK (4.4) and Australia (4.4). From 2003 to 2023, the average annual increase of ASIRs in Hong Kong (AAPC = 0.99%, 95% CI: 0.73–1.26) was comparable to Australia (0.51%, 0.03–1.01) and US (0.57%, 0.37–0.82), but slower than UK (1.80%, 1.48–2.13), Japan (2.95%, 2.36–3.54), Korea (3.89%, 2.86–4.66) and mainland China (4.37%, 4.02–4.71). ASMRs declined in Hong Kong (AAPC = -2.08%, 95% CI: -2.51– -1.65) and Korea (-2.53%, -2.89– -2.18), showing a smaller decrease than mainland China (-3.30%, -3.58– -3.01), but larger than US (-0.86%, -1.06– -0.68), UK (-1.20%, -1.50– -0.92), Japan (-1.40%, -1.64– -1.16) and Australia (-1.67%, -1.88– -1.49). Among males in Hong Kong, leading cancer types included leukemia (ASIR = 4.75), nasopharyngeal cancer (ASIR = 3.19) and testicular cancer (ASIR = 2.57) over the past two decades. Female incidence patterns were more stable, dominated by breast cancer (ASIR = 7.56), thyroid cancer (ASIR = 5.38) and leukemia (ASIR = 3.62). Notably, nasopharyngeal cancer incidence in Hong Kong (male ASIR: 3.19; female: 1.08) was more than 10-fold higher than in other regions for both sexes, likely due to endemic EB virus exposure, genetic susceptibility, and region-specific environmental factors. Conclusions: CAYA cancer burden in Hong Kong remains comparatively low versus neighboring East Asian and Western countries, with declining mortality but rising incidence in recent years. High incidence of selected cancer highlights the need for ongoing surveillance, tarted prevention, and strengthened survivorship care.