Socioeconomic Disparities in Colon Cancer Survival: Revisiting Neighborhood Poverty using Residential Histories.

BACKGROUND Residential histories linked to cancer registry data provide new opportunities to examine cancer outcomes by neighborhood socioeconomic status (SES). We examined differences in regional-stage colon cancer survival estimates comparing models using a single neighborhood SES at diagnosis to models using neighborhood SES from residential histories. METHODS We linked regional-stage colon cancers from the New Jersey State Cancer Registry diagnosed from 2006-2011 to LexisNexis administrative data to obtain residential histories. We defined neighborhood SES as census tract poverty based on location at diagnosis, and across the follow-up period through 31 December 2016 based on residential histories (average, time-weighted average, time-varying). Using Cox proportional hazards regression, we estimated associations between colon cancer and census tract-poverty measurements (continuous and categorical), adjusted for age, gender, race/ethnicity, regional substage, and mover status. RESULTS Sixty-five percent of the sample were non-movers (one census tract); 35% (movers) changed tract at least once. Cases from tracts with >20% poverty changed residential tracts more often (42%) than cases from tracts with 20%) had a 30% higher risk of regional-stage colon cancer death than cases in the lowest category (<5%) (95% confidence interval [CI] 1.04-1.63). CONCLUSION Residential changes after regional-stage colon cancer diagnosis may be associated with a higher risk of colon cancer death among cases in high-poverty areas. This has important implications for post-diagnostic access to care for treatment and follow-up surveillance.