A rare analysis of cancer mortality in the United States by county rather than by state shows that, although the death rates overall have steadily declined, there are pockets where the rates have dramatically increased. Breaking these data down into smaller geographic units can help identify areas of focus for local public health programs and for additional research to understand the causes.

Age-standardized mortality rate from neoplasms, both sexes, 2014. Image courtesy of the JAMA Network (C) 2017 American Medical Association.

The researchers, from the University of Washington's Institute for Health Metrics and Evaluation, used deidentified death records from the National Center for Health Statistics (NCHS); population data from the NCHS, the Census Bureau, and the Human Mortality Database; and "small area regression" models for county-level mortality rates for 29 cancers. Cancer mortality decreased in the United States by 20% between 1980 and 2014, but in 160 of the nation's 3,000 counties mortality significantly increased for certain cancers-for example, breast cancer in parts of the South; liver cancer in parts of Texas; and kidney cancer in areas of North and South Dakota, West Virginia, Ohio, Indiana, Louisiana, Oklahoma, Alaska, and Illinois. Among possible explanations cited by the researchers for these differences are a combination of risk factors and inadequate prevention and screening, delayed cancer detection owing to lack of screening awareness among patients and clinicians, poor access to care, and inadequate treatment.

The magnitude of the differences was a surprise, the lead investigator, Ali Mokdad, PhD, told the National Cancer Institute's cancer research blog, Cancer Currents, on February 21. Knowing the specifics, though, is key: "You can't change anything in public health unless you are able to measure [and] monitor it. We wanted counties to know their 'number,' and empower public health professionals to take action."

Writing in an accompanying editorial, two researchers at the University of North Carolina Gillings School of Global Public Health, agreed, and noted: "The reality is that barriers to cancer prevention and control are not one size fits all in communities with higher cancer mortality; therefore, policies and interventions targeting those regions cannot be one size fits all."-Serena Stockwell

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