Factors associated with breast cancer mortality-per-incident case in low-to-middle income countries (LMICs)

Background: Reducing breast cancer mortality is a key healthcare challenge worldwide. We sought to determine the impact of macro-socioeconomic factors on breast cancer age-standardized incidence (ASI) and mortality-per-incident case (MPI) in LMICs. Methods: Data regarding breast cancer ASI and mortality in 78 LMICs were obtained from IARC/WHO. MPI was defined as the age standardized mortality divided by the ASI. Country-level socioeconomic data were obtained from World Bank, UN Development Project, and WHO data sources. Results: In 2018, the median ASI for breast cancer was 26.5 (range; 5-67.3) per 100,000 population in LMICs, with a median MPI of 50.6% (range 27-70%). ASI and MPI were inversely correlated (Spearman rho = -0.236, p = 0.044). Factors associated with ASI and MPI are shown in the table below. We found no factor could discriminate between the highest and lowest quartile in terms of ASI. However, all (except health expenditure as a % of GDP) were significantly different between the highest and lowest quartile in terms of MPI. Conclusions: Results suggest considerable variation in terms of breast cancer MPI within LMICs. Improved rates are seen with increasing GDP, literacy, contraceptive use, and provision of doctors and mammography, but overall % GDP expended on public health does not seem to significantly influence breast cancer MPI.