The Impact of Income and Social Mobility on Colorectal Cancer Outcomes and Treatment: A Cross-sectional Study.

Objective: To determine the impact of income mobility on racial disparities in colorectal cancer.

Background: There are well-documented disparities in colorectal cancer treatment and outcomes between Black and White patients. Socioeconomic status, insurance, and other patient-level factors have been shown important, but little has been done to show the discriminatory factors that lead to these outcomes.

Methods: Data were obtained from the Surveillance Epidemiology and End-Results database for Black and White patients with colorectal cancer between 2005 and 2015. County level measures of Black (BIM) and White income mobility (WIM) were obtained from the Opportunity Atlas as a measure of intergenerational poverty and social mobility. Regression models were created to assess the relative risk of advanced stage at diagnosis (Stage IV), surgery for localized disease (Stage I/II), and cancer-specific mortality.

Results: There was no significant association of BIM or WIM on advanced stage at diagnosis in Black or White patients. An increase of $10,000 of BIM was associated with a 9% decrease in hazards of death for both Black (hazard ratio 0.91, 95% confidence interval 0.86,0.95) and White (0.91, 95%CI 0.90,0.93) patients, while the same increase in WIM was associated with no significant difference in hazards among Black patients (hazard ratio 0.99, 95% confidence interval 0.97,1.02). There were no predicted racial differences in hazards of death at high levels of BIM.

Conclusions: Increased Black income mobility significantly improves survival for both Black and White patients. Interventions aimed at increasing economic and social mobility could significantly decrease mortality in both Black and White patients while alleviating disparities in outcomes.