Differences in late-stage cancer risk between urban and rural residents are a key component of cancer disparities. Using data from the Illinois State Cancer Registry from 1998 through 2002, the authors investigated the rural-urban gradient in late-stage cancer risk for 4 major types of cancer: breast, colorectal, lung, and prostate.METHODS:
Multilevel modeling was used to evaluate the role of population composition and area-based contextual factors in accounting for rural-urban variation. Instead of a simple binary rural-urban classification, a finer grained classification was used that differentiated the densely populated City of Chicago from its suburbs and from smaller metropolitan areas, large towns, and rural settings.RESULTS:
For all 4 cancers, the risk was highest in the most highly urbanized area and decreased as rurality increases, following a J-shaped progression that included a small upturn in risk in the most isolated rural areas. For some cancers, these geographic disparities were associated with differences in population age and race; for others, the disparities remained after controlling for differences in population composition, zip code socioeconomic characteristics, and spatial access to healthcare.CONCLUSIONS:
The observed pattern of urban disadvantage emphasized the need for more extensive urban-based cancer screening and education programs.
For breast, colorectal, lung, and prostate cancers in Illinois, the risk of a late-stage diagnosis was highest in the City of Chicago and decreased with increasing rurality and followed an inverse, J-shaped gradient that included an upturn in risk in the most isolated rural areas.