Socioeconomic status and survival after an invasive breast cancer diagnosis.

Background: Women who live in geographic areas with high poverty rates and low levels of education experience poorer survival after a breast cancer diagnosis than women who live in communities with indicators of high socioeconomic status (SES). However, very few studies have examined individual-level SES in relation to breast cancer survival or have assessed the contextual role of community-level SES independent of individual-level SES.

Methods: The authors of this report examined both individual-level and community-level SES in relation to breast cancer survival in a population-based cohort of women ages 20 to 69 years who were diagnosed with breast cancer in Wisconsin between 1995 and 2003 (N = 5820).

Results: Compared with college graduates, women who had no education beyond high school were 1.39 times more likely (95% confidence interval [CI], 1.10-1.76) to die from breast cancer. Women who had household incomes <2.5 times the poverty level were 1.46 times more likely (95% CI, 1.10-1.92) to die from breast cancer than women who had household incomes ≥5 times the poverty level. Adjusting the analysis for use of screening mammography, disease stage at diagnosis, and lifestyle factors eliminated the disparity by income, but the disparity by education persisted (hazard ratio [HR], 1.27; 95% CI, 0.99-1.61). In multilevel analyses, low community-level education was associated with increased breast cancer mortality even after adjusting for individual-level SES (HR, 1.57; 95% CI, 1.09-2.27 for ≥20% vs <10% of adults without a high school degree).

Conclusions: The current results indicated that screening and early detection explain some of the disparity according to SES, but further research will be needed to understand the additional ways in which individual-level and community-level education are associated with survival.