The mortality data are possibly more telling. High incidence may be a matter of screening and early detection. Dead bodies have stories to tell and are harder to hide.
The outline of the Ohio-Mississippi river valleys is particularly clear.
The mortality map shows equivalent death rates across borders. Indiana, Kentucky, Illinois, Arkansas, Mississippi and Louisiana. And is markedly higher in non-urban (and desperately poor) counties. By contrast, incidence rates (clinical detection preceding mortality) clusters more toward urban and wealthier counties.
The outline of the Ohio-Mississippi river valleys is particularly clear.
https://statecancerprofiles.cancer.gov/map/map.withimage.php...