Burdens of gastric and colorectal cancers among the Western Pacific region and their association with human resources for health, 2000-2021: a systematic analysis of the Global Burden of Disease Study 2021

Background: Stomach cancer (SC) and colorectal cancer (CRC) are two leading gastrointestinal cancers globally, imposing significant burdens in the Western Pacific region (WPR). This study aimed to comprehensively describe the regional landscape and temporal trends for the burdens of SC and CRC in the WPR. The associations between their burdens and human resources for health (HRH) were also explored to inform health policy and investment. Methods: Data on incidence, disability-adjusted life years (DALYs), and deaths for SC and CRC were obtained from the Global Burden of Disease Study (GBD) 2021, and the annual density of HRH was retrieved from GBD 2019. Estimated annual percentage changes (EAPCs) were calculated to reflect the trends in age-standardized incidence rates (ASIR), age-standardized DALY rates (ASDR), and age-standardized mortality rates (ASMR). Pearson correlation analysis was performed to examine associations between the burdens and HRH density. Findings: In 2021, the incident cases of SC and CRC in the WPR accounted for 61.77% and 43.07% of the global totals, respectively. From 2000 to 2021, the ASIR (EAPC=-2.30, 95% CI -2.44 to -2.16), ASDR (EAPC=-3.41, 95% CI -3.59 to -3.23), and ASMR (EAPC=-3.11, 95% CI -3.29 to -2.94) of SC decreased. Conversely, the ASIR of CRC increased by an average of 1.32% (95% CI 1.25% to 1.39%), while ASDR (EAPC=-0.48, 95% CI -0.59 to -0.38) and ASMR (EAPC=-0.45, 95% CI -0.53 to -0.37) of CRC declined. China exhibited the highest numbers of incident cases, DALYs, and deaths for both cancers among the 31 WPR countries or territories. An increase in the ASDRs of SC was detected in Guam. Meanwhile, Viet Nam experienced the fastest rise in ASIR of CRC, followed by China and Philippines. The number of incident cases, DALYs, and deaths of both SC and CRC followed a bell-shaped distribution with a peak in individuals aged 65-74 years. The rates of incidence, DALY, and mortality were generally higher in males than in females. HRH density was negatively correlated with the ASDR (r=-0.41, P=0.021) and ASMR (r=-0.37, P=0.040) of SC in 2019, but positively correlated with ASDR (r = 0.41, P=0.024) and ASMR (r=0.51, P=0.003) of CRC. Additionally, HRH density was negatively associated with the EAPCs of ASDR (r=-0.40, P=0.024) and ASMR (r=-0.41, P=0.021) for SC, and the EAPCs of ASDR (r=-0.65, P<0.001) and ASMR (r=-0.66, P<0.01) for CRC, especially for dieticians &amp; nutritionists, radiographers, and optometrists. Interpretation: SC and CRC remain noticeable public health issues in the WPR, necessitating increased attention to countries and territories with high or rising burdens of these cancers. The negative correlations between EAPCs of ASDR and ASMR with HRH density suggested that increasing investment for health workers, particularly dieticians &amp; nutritionists, radiographers, and optometrists, may help mitigate increasing trends or enhance declining trends in the burdens of SC and CRC.