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.
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.
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 <5% poverty (32%). Hazard ratios (HRs) were generally similar in strength and direction across census tract-poverty measurements. In time-varying models, cases in the highest poverty category (>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).
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.