Impacts of Neighborhood Characteristics on Treatment and Outcomes in Women with Ductal Carcinoma of the Breast.

This study examines associations of neighborhood characteristics with treatment and outcomes of ductal carcinoma (DCIS) of the breast. From the Missouri Cancer Registry, we identified 9,195 women with DCIS diagnosed between 1996 and 2011. A composite index using U.S. Census data and American Community Survey data was developed to assess census tract-level socioeconomic deprivation, and rural-urban commuting area codes were used to define rural census tracts. ORs and 95% confidence intervals (CIs) of the treatment were estimated using logistic regression. Hazard ratios (HRs) of DCIS outcomes were estimated using Cox proportional hazards regression. Women in the most socioeconomically deprived census tracts were more likely than those in the least deprived to have mastectomy (OR = 1.44; 95% CI, 1.25-1.66; < 0.0001), no surgery (OR = 1.54; 95% CI, 1.02-2.30; = 0.04), no radiotherapy post-breast conserving surgery (OR = 1.90; 95% CI, 1.56-2.31; <0.0001), delayed radiotherapy (OR = 1.26; 95% CI, 1.01-1.57; = 0.02), and ipsilateral breast tumors (HR = 1.59; 95% CI, 1.07-2.38; = 0.03). There was no significant difference in risk of contralateral breast tumors. Compared with urban women, rural women had significantly higher odds of underutilization of radiotherapy (OR = 1.29; 95% CI, 1.08-1.53). Rural locations were not associated with risk of ipsilateral or contralateral breast tumors. Neighborhood socioeconomic deprivation was associated with higher risks of suboptimal treatment and ipsilateral breast tumors. While DCIS treatment significantly varied by rural/urban locations, we did not observe any statistically significant rural-urban differences in risks of second breast tumors. Neighborhood attributes may affect treatment and outcomes of patients with DCIS.