Disparities in Cancer Incidence and Mortality in Rural Versus Urban Michigan

Rurality is one of many disparities leading to lower cancer screening rates, as well as higher cancer incidence and mortality. Our study was designed to evaluate rural-urban disparities in incidence and cancer-specific mortality for the leading cancers in the State of Michigan from January 1, 2017, through December 31, 2021.

Data was obtained for the 10 leading cancers in both incidence and cancer-specific mortality from the Michigan Department of Health and Human Service. Rural-urban comparisons were made for incidence, incidence by SEER stage, and cancer-specific mortality and reported as rate ratios.

Combining the 10 leading cancers in Michigan during our study period, the age-adjusted incidence rate was significantly lower (IRR 0.95, 95% CI 0.94-0.96, p < 0.001), whereas the age-adjusted cancer-specific mortality rate was significantly higher (MRR 1.05, 95% CI 1.03-1.07, p = 0.023) in our rural study population. Regarding cancers with proven screening benefits, age-adjusted incidence rates and cancer-specific mortality rates for female breast (IRR 0.87; 95% CI 0.85-0.89; p < 0.001 and MRR 0.87; 95% CI 0.81-0.98; p = 0.012) and prostate (IRR 0.86; 95% CI 0.83-0.88; p < 0.001 and MRR 0.92; 95% CI 0.86-0.98; p = 0.012) cancer were significantly lower in rural Michigan. Lung and bronchus cancer had significantly higher age-adjusted incidence rates and cancer-specific mortality rates in our rural study population (IRR 1.07; 95% CI 1.05-1.10; p < 0.001 and MRR 1.17; 95% CI 1.14-1.20; p < 0.001).

Our rural Michigan population had significantly lower incidence rates for the 10 leading cancers in incidence, female breast cancer, and prostate cancer in our study period. However, rurality was associated with higher age-adjusted cancer-specific mortality for the 10 leading cancers regarding mortality and for lung and bronchus cancer. Continued focus on Michigan's existing public health programs may further bridge rural disparity gaps.