Global incidence, mortality and temporal trends of cancer in children: A joinpoint regression analysis

The Cancer Incidence in Five Continents Time Trends, Nordic Cancer Registries, Surveillance, Epidemiology and End Results, WHO Mortality databases were assessed to extract the Age-Standardised Rates (ASR) of cancer incidence and mortality among children aged 0-14 years old. By using the ASRs, the country-specific Average Annual Percentage Change (AAPC) and its corresponding 95% confidence interval (CI) were calculated to determine the epidemiological cancer trend.

In 2020, the highest incidence of childhood cancer was found in countries with higher Human Development Index (HDI) (ASR = 15.7), yet the highest mortality was found in countries with lower HDIs (ASR = 4.8). As for incidence, seven countries had positive AAPC among boys; Slovakia (AAPC_2001-2010  = 4.98, 95% CI [1.66-8.40]), Ecuador (AAPC_2003-2012  = 4.07, 95% CI [0.67-7.59]) and Thailand (AAPC_2003-2012  = 3.69, 95% CI [0.37-7.11]) had the highest AAPC. Among girls, three countries had positive AAPC, which included Belarus (AAPC_2003-2012  = 3.18, 95% CI [1.11, 5.29]), Canada (AAPC_2003-2012  = 2.83, 95% CI [1.60, 4.07]) and Korea (AAPC_2003-2012  = 1.76, 95% CI [0.23-3.32]). There was an overall decreasing trend of mortality. However, increased mortality was observed in two countries: Ecuador for boys (AAPC_2007-2016  = 1.72, 95% CI [0.27-3.19]) and Austria for girls (AAPC_2008-2017  = 4.11, 95% CI [0.38-7.98]).

The largest mortality and mortality to incidence ratio of childhood cancer were found in low-income countries. There was a substantial increasing trend of childhood cancer incidence, while overall its mortality has been decreasing over the past decade. More studies are needed to confirm the drivers behind these epidemiologic trends.