Neoplasms represent a significant category of noncommunicable diseases (NCDs) contributing to global mortality and disability, posing a critical public health challenge worldwide. Globocan 2022 data revealed 19.96 million new neoplasm cases and 9.74 million deaths worldwide, with lung, breast (female), and colorectal cancers constituting the predominant malignancies. Projected cancer incidence will reach 35 million annually by 2050 (77% increase from 2022), with nations scoring low on the Human Development Index (HDI) projected to experience a 142% surge, driven by demographic transitions. Demographic expansion, population aging, deficient screening systems, and constrained treatment access in low-HDI regions drive these trends, creating an imperative for equitable allocation of global oncology resources1.
Low physical activity (LPA) is an established modifiable determinant for major NCDs, spanning malignancies, metabolic disorders, and neuropsychiatric conditions2,3,4. LPA constitutes a significant global health burden, demonstrating a 6.6% age-standardized prevalence rise since 2000 and contributing to 7.2% of global all-cause mortality in 20225,6. Moderate physical activity (PA) confers significant protection against breast (HR 0.90; 95% CI: 0.87–0.93), colon (HR 0.84; 95% CI: 0.77–0.91), and rectal cancers (HR 0.87; 95% CI: 0.80–0.95), with parallel reductions in site-specific mortality7. To promote essential PA worldwide, numerous countries and regions have developed national PA guidelines tailored to their specific contexts (e.g., Canada, the UK, and the US), which have been widely disseminated through organizations such as the World Health Organization (WHO) and the European Union. Regrettably, only 72.5% of adults globally meet the minimum recommended PA levels outlined in public health guidelines8.
Mitigating low physical activity-attributable neoplasm burden is pivotal to achieving the UN Sustainable Development Goal (SDG) 2030 target: one-third reduction in premature NCDs mortality via prevention and care9. Generating robust evidence to elucidate the relationship between LPA and neoplasms is essential for guiding future healthcare policies. The Global Burden of Diseases, Injuries, and Risk Factors Study 2021 (GBD 2021) provides comparable population-level estimates of mortality, disability-adjusted life years (DALYs), and risk-attributable burden across 204 countries and territories from 1990 to 2021 using standardized epidemiological approaches. In GBD 2021, disease and injury estimates cover 371 diseases and injuries, while the risk factor analysis estimates exposure, relative risk, population attributable fractions, and attributable burden for 88 risk factors10. However, fewer studies have provided a stepwise and reproducible workflow for extracting GBD 2021 low physical activity-attributable neoplasm data and applying trend, decomposition, inequality, and projection analyses within a single protocol. This manuscript addresses this methodological gap by detailing the data extraction, variable definition, statistical modeling, and interpretation procedures for this specific GBD risk-outcome pairing. This protocol describes a reproducible secondary analysis of GBD 2021 estimates for neoplasms attributable to low physical activity across 204 countries and territories from 1990 to 2021, with projections to 2045. The objectives were to quantify deaths, DALYs, age-standardized rates, temporal trends, decomposition components, socioeconomic inequalities, and projected burden, without inferring individual-level causality or direct intervention effects.
This workflow was chosen because it integrates several complementary analytical components into a single reproducible framework. Compared with studies that report only descriptive GBD estimates or single trend metrics, this protocol combines burden estimation, EAPC, joinpoint regression, decomposition analysis, inequality assessment, and BAPC projection, allowing users to examine not only the magnitude of burden but also temporal changes, demographic drivers, socioeconomic gradients, and future trends. The protocol is applicable to researchers conducting secondary analyses of GBD risk-attributable estimates, particularly when the aim is to compare burden patterns across time, sex, age groups, countries, regions, or SDI categories.