A new nationwide study conducted by American Cancer Society (ACS) researchers reports a long-term shift in the overall cancer burden from urban to rural areas in the U.S. -- but also specifically for breast and lung cancer.
The shift is likely due to differences in cancer risk factors and in access to early detection and treatment, said lead author Farhad Islami, MD, PhD, of the ACS, in a statement. The findings were published March 19 in the Journal of the National Cancer Institute.
"Unfortunately, these trends largely reflect growing inequalities in social determinants of health," he noted.
Higher cancer mortality rates for rural residents in the U.S. are driven by limited access to care, lower screening rates, higher poverty, and higher prevalence of smoking. Understanding long-term trends in cancer mortality across rural and urban areas can provide additional insight into the factors contributing to rural-urban disparities and inform public policy, according to Islami and colleagues.
For the report, the team examined age-standardized mortality rates across four categories of urbanicity using National Center for Health Statistics data from 1969 through 2023, encompassing more than 27 million cancer deaths.
The group reported that urban breast cancer mortality rates began to decline between 1990 and 1992, likely due to the broad adoption of screening mammography and advances in systemic treatment during that period. But the pace of this decline varied by geography, Islami and co-authors explained: In large metropolitan areas, mortality fell steadily through 2023, while in the most rural counties -- that is, those with fewer than 5,000 urban residents -- the decline decreased and plateaued after 2010. As a result, breast cancer mortality rates that were lower in rural counties between 1969 and 1971 (26.4 per 100,000 vs. 34.3 in large metropolitan areas) converged and now surpass urban rates (20.7 vs. 18.4 per 100,000 between 2021 and 2023).
The study also found that rural-urban breast cancer incidence trends were comparable between 2000 and 2019, which the investigators posited had to do more with differential screening use and access to treatment rather than underlying risk factor exposure. Although mammography uptake increased in both rural and urban areas between 1994 and 2004, absolute screening prevalence remained consistently lower in rural populations throughout the study period.
In terms of overall cancer findings, the report noted that between 1969 and 1971, large urban counties recorded the highest all-cancer mortality rates in both men (264.6 per 100,000) and women (169.7 per 100,000), with rates declining in the most rural areas. But between 2021 and 2023, this phenomenon reversed: nonmetropolitan counties with fewer than 5,000 urban residents now carry the highest mortality burden (197.9 per 100,000 in men and 144.3 per 100,000 in women), while large metropolitan areas record the lowest rates (157.4 per 100,000 in men and 118.9 per 100,000 in women).
Lung cancer accounted for the largest part of this reversal, the team wrote: Among men, the most rural counties shifted from a mortality rate 26% below that of large urban areas between 1969 and 1971 to a rate of 55% above that of large urban areas between 2021 and 2023.
The authors attributed the overall cancer burden shift to the geographic redistribution of social determinants of health such as income, employment, health insurance coverage, and access to oncology specialists and comprehensive cancer centers, noting that in 2019, roughly two-thirds of all U.S. counties -- concentrated in rural areas -- lacked an oncologist with a primary practice location within the county, and rural hospital closures have further eaten away at access to cancer services.
These findings underscore the need for targeted policy interventions across the full cancer continuum, the group concluded.
"All people -- no matter where they live -- should have a fair and just opportunity to prevent, detect, treat, and survive cancer," said Lisa Lacasse, president of the ACS Cancer Action Network, in the society's statement. "This study highlights the need for lawmakers to support policies that help improve access to comprehensive, affordable health care and ensure health plans maintain strong and robust networks, so patients have access to the health care professionals and treatments they need. Doing so will help reduce the cancer burden for everyone."
Access the full report here.
