Differences in the incidence and mortality of digestive cancer between Global Cancer Observatory 2020 and Global Burden of Disease 2019

The burden of digestive cancers is increasing worldwide. The Global Cancer Observatory (GLOBOCAN) 2020 and the Global Burden of Disease (GBD) 2019 are two primary cancer databases, which have a significant impact on policy formulation and resource allocation. We aim to compare the incidence and mortality of digestive cancers between them. Digestive cancer (esophageal, stomach, colorectal, liver, gallbladder and pancreatic cancer) incidence was obtained from the Cancer Today and GBD 2019 result tool. The top five countries with the most or minor difference between GLOBOCAN 2020 and GBD 2019 in age-standardized incidence rates (ASIRs) of digestive cancers were identified. A systematic search on the incidence of specific digestive cancer in selected countries from PubMed and Embase was conducted, and 20 of 281 publications were included. The most significant differences in digestive cancers incidence were commonly found in Asian countries (70%), particularly Indonesia, Vietnam and Myanmar, located in Southeast Asia. The ASIRs for most digestive cancers, except liver cancer, in GLOBOCAN 2020 were higher than those in GBD 2019. Gallbladder cancer had the highest average ratio, followed by liver cancer. The most commonly used standard population was Segi's standard population, followed by the World Health Organization standard population. The data sources nor the processing methods of GLOBOCAN 2020 and GBD 2019 were not similar. Low- and middle-income countries without population-based cancer registries were more likely to have selection bias in data collection and amplify regional variations of etiological factors. Better judgments on the quality of cancer data can be made.