Rural-urban breast cancer mortality gap projected to widen through 2035

Research from Case Western Reserve University shows that the mortality gap between rural and urban breast cancer patients is projected to widen to 13% by 2035, reaching 3.8 excess deaths per 100,000 women in rural areas. While overall mortality declined from 1999 to 2020, rural rates lagged behind, becoming consistently higher by 2013. Key drivers of excess rural deaths include county-level income (45.3%), late-stage diagnosis (24.9%), and radiation omission (11.4%).

Projections for future mortality gap

• ▪The gap in age-adjusted breast cancer mortality between rural and urban populations is projected to widen from two deaths per 100,000 in 2020 to 3.8 deaths per 100,000 by 2035.
• ▪Researchers projected that the age-adjusted breast cancer mortality rate in rural populations will be approximately 13% higher than in urban populations by 2035.

Historical mortality trends and rate disparities

• ▪A Case Western Reserve University study presented at the 19th AACR Conference found that breast cancer mortality declined across rural and urban populations between 1999 and 2020.
• ▪Rural breast cancer mortality surpassed urban mortality in 2005 and remained consistently higher beginning in 2013, reaching a rate 7% higher than urban populations by 2020.
• ▪Analysis of 1,156,445 breast cancer deaths in the CDC WONDER database showed 2020 age-adjusted rates of 32.51 per 100,000 in rural areas compared to 30.48 per 100,000 in urban areas.

Unadjusted versus adjusted mortality risk

• ▪After adjusting for age, race, ethnicity, tumor stage, molecular subtype, chemotherapy, and radiotherapy, rural patients maintained a 3% higher risk of breast cancer death than urban patients.
• ▪Rural breast cancer patients faced a 21% higher unadjusted risk of breast cancer-related death compared to urban patients in the NCI SEER database between 2000 and 2020.

Factors contributing to excess rural deaths

• ▪A Case Western Reserve University study identified county-level income as the primary contributor to excess rural breast cancer deaths, accounting for 45.3% of the disparity.
• ▪Analysis of SEER database records showed that race and ethnicity were not contributors to the rural-urban disparity in breast cancer mortality.
• ▪A study found advanced stage at diagnosis accounted for 24.9% of excess rural breast cancer deaths, while radiation omission and chemotherapy omission accounted for 11.4% and 7.9% respectively.

Barriers to care and proposed solutions

• ▪Case Western Reserve University presenter Nickolas Stabellini stated that addressing financial barriers and improving healthcare access along multiple points of a patient's treatment journey will be necessary to reduce disparities.
• ▪Nickolas Stabellini stated that rural breast cancer patients face greater challenges obtaining screening, accessing timely diagnostic testing, seeing specialists, and traveling repeatedly for treatment.