Geographers can bring a unique spatial perspective to topics in a variety of disciplines. Zhao et al. (2020) use spatial statistics to improve our understanding of breast cancer. To do so, they analyze the spatial variation in the incidence rate of female breast cancer across the United States. This is the largest scale study, as far as the authors know, in terms of geographic extent, the number of risk factors considered, and the consideration of multiple races/ethnicities.

Zhao et al. (2020) consider a diverse range of demographic, socioeconomic, lifestyle, health accessibility, environmental, and living condition variables as potential risk factors for breast cancer. Previous studies of cancer at the population level have been confined to a narrower range of variables, often using poverty as the only socioeconomic factor. Recent research at smaller geographic scales indicates a variety of socioeconomic factors that are important predictors of breast cancer: the percentage of female-headed households, the percentage of the lower-educated population, and the percentages of recent immigrants. Studies have also associated racial and income inequality with female breast cancer risk. Using county-level census data from the whole country and advanced spatial statistical techniques, Zhao et al. (2020) surpass the scope of previous work.

Race emerges as the most influential factor on the rate of breast cancer across U.S. counties. Non-Hispanic whites have significantly higher incidence rates. Lower income and lower educational attainment are also associated with higher cancer rates, as well as lower health accessibility. These findings are all consistent with prior research.

By controlling for these well-known associations, the authors identify new socioeconomic and environmental risk factors for breast cancer. Counties with a higher percentage of married families tend to have lower cancer rates. Moreover, counties with better air quality tend to have lower cancer rates.

Cancer researchers can take away from this study the need for a deeper understanding of the effects of air pollution. Local governments and health organizations can use it to plan intervention strategies for reducing breast cancer risk.

This post is a summary of Zhao et al.’s (2020) piece, “Identifying county-level factors for female breast cancer incidence rate through a large-scale population study,” summarized by COSSPP blog researcher, Jesse Fried.