Global burden, geographic and sex disparities, and projections to 2050 for salivary gland cancer across G20 countries: a GLOBOCAN 2024 analysis

Background Salivary gland cancer is uncommon, and neither its distribution nor its trajectory across the G20 has been well described. Using the GLOBOCAN 2024 case counts, we described the 2024 burden in the 19 G20 member economies and in four HDI aggregates, and examined HDI-related gradients in population-level proxies for survival. Methods We analyzed the GLOBOCAN 2024 case counts for salivary-gland cancer (ICD-10 C07–C08) in the 19 G20 member economies and four HDI groups. Age-standardized incidence (ASIR) and mortality (ASMR) rates, 5-year prevalence, and the mortality-to-incidence (MIR) and prevalence-to-mortality (PMR) ratios were tabulated by country, HDI group and sex, and related to HDI using Spearman rank correlation. Projections to 2050 follow the GLOBOCAN 2024 Cancer Tomorrow default demographic scenario, applying the 2024 case counts and age-specific rates to United Nations population projections. Results In 2024 the G20 recorded 37,812 cases and 12,661 deaths, 46.2% of them in China and India. At country level, the HDI–MIR correlation was not significant (r = −0.04, 95% CI −0.48 to 0.42; P = 0.88), although MIR was highest in the low-HDI group (0.53) and lowest in the very-high-HDI group (0.34) and PMR varied 3.9-fold across aggregates. Male MIR exceeded female MIR in 16 of the 17 economies for which the ratio was computable, the sole exception being Türkiye. Holding 2024 age-specific rates constant, deaths at ages ≥75 years would rise by 152.8% by 2050; growth would be largest in the low- and medium-HDI aggregates (+134.4% and +96.1%) and smallest in Japan (+8.4%). Conclusion The G20 burden was highly heterogeneous. Across the global HDI aggregates the burden followed development level, with the highest MIR in the low-HDI group, but this ordering did not carry over to a country-level HDI–MIR correlation among the 19 member economies. Projected growth was concentrated in low- and medium-HDI settings, which argues for strengthening diagnostic capacity and survivorship measurement there.