Multilevel Influences of Social, Demographic and Economic Determinants on Late Stage Colorectal Cancer Diagnosis

Large variations in colorectal cancer incidence across states and counties have been widely reported. Area socioeconomic status (SES) has been found to associate with risk of incidence and late-stage diagnosis. It is, however, unclear if the associations remain significant for smaller geographic units where SES-related contextual neighborhood effects can be measured more precisely. Our study employs census tract level data to identify factors associated with racial/ethnic disparities in stage of cancer diagnosis.

Colorectal cancer data for 1995-2007 (n=14,108) were obtained from Texas Cancer Registry for Houston (592 census tracts). The late-stage diagnosis outcome was defined by the tumor having spread regional or distant. Census tract SES variables were aggregated from the 2000 Census data (poverty, wealth, income and linguistic isolation). Generalized linear mixed models were employed to predict late-stage diagnosis on neighborhood SES and individual characteristics (gender, age, race/ethnicity).

Only neighborhood poverty, age and race/ethnicity exhibited a significant (p<.05) association. Average late-stage diagnosis would increase by 0.2 percentages per one percentage increase in poverty level. Younger patients had a small but elevated risk to be diagnosed late (probability decreased by 0.06 percentages per year). Finally, Hispanics had the highest risk for late-stage diagnosis (1.29 times more likely than whites). Our results confirm neighborhood poverty plays a key role in the pathway other socio-demographics influence late-stage diagnosis. Contrary to previous reports, our findings about Hispanics suggest lack of access to cancer screening contributes to poor cancer outcomes and public and easy access to such services is particularly critical to this population.