Breast cancer stage variation and survival in association with insurance status and sociodemographic factors in US women 18 to 64 years old

BACKGROUND: Few population-based studies have examined the association between health insurance status and breast cancer stage at diagnosis and survival. The degree to which sociodemographic characteristics explain this association is also unclear. This study examined associations between insurance status and sociodemographic characteristics and stage at diagnosis and survival. METHODS: Using the Surveillance, Epidemiology, and End Results 18 registries database, we identified 52,048 women aged 18 to 64 years who were diagnosed with breast cancer in 2007 and 2008. Associations between insurance status and sociodemographic variables and stage at diagnosis and survival were examined with logistic and Cox proportional hazards regression models to calculate adjusted odds ratios (ORs), hazard ratios (HRs), and associated confidence intervals (CIs). RESULTS: The odds of a later stage breast cancer diagnosis were increased in women with Medicaid (OR, 2.36; 95% CI, 2.19-2.55) and no insurance (OR, 2.64; 95% CI, 2.29-3.04) versus private insurance, in women who had reported black race (OR, 1.18; 95% CI, 1.09-1.28) versus white race, in women who were unmarried (OR, 1.25; 95% CI, 1.18-1.33) versus married at diagnosis, and in women who were 18 to 39 years old (OR, 1.29; 95% CI, 1.18-1.41) versus 40 to 64 years old at diagnosis. The hazard of breast cancer death was increased in association with Medicaid (HR, 1.40; 95% CI, 1.30-1.51) and no insurance (HR, 1.61; 95% CI, 1.41-1.84) versus private insurance, with reported black race (HR, 1.39; 95% CI, 1.29-1.50) versus reported white race, and with being unmarried (HR, 1.19; 95% CI, 1.12-1.27) versus being married. CONCLUSIONS: Insurance status at diagnosis and sociodemographic factors are associated with breast cancer mortality. Factors underlying these associations warrant further study. Cancer 2017;123:3125-31. © 2017 American Cancer Society.