Abstract P1-09-12: The interplay of biologic factors, race, and delivery of care in improving breast cancer outcomes

Abstract

Abstract Importance: A marked disparity exists in the breast cancer mortality of women diagnosed in Eastern North Carolina (ENC) when compared to women diagnosed in the rest of North Carolina (RNC). Objective: To identify modifiable factors associated with the increased mortality of women diagnosed with breast cancer in ENC. Design: Retrospective cohort study of women diagnosed with breast cancer in North Carolina between January 1, 2004 and December 31, 2007. Setting: North Carolina Central Cancer Registry. Participants: Females diagnosed with either invasive or non-invasive breast cancer in North Carolina during the designated time period. Main Outcome Measures: Race/ethnicity, hormone receptor status, pathologic T, N and stage grouping at the time of diagnosis, delivery of adjuvant chemotherapy, and survival. Results: A total of 27,631 women were diagnosed with breast cancer during the study period. Women in ENC were slightly older than in RNC (59.2 y v. 58.5 y, p<0.001). There was no difference in the pathologic T (p = 0.62), N (p = 0.26) or Stage Grouping (p = 0.25) at diagnosis between ENC and RNC patients. Women in ENC were less likely to be White (68.9% v. 80.0%, <0.001)), ER positive (53.4% v. 59.4%, p<0.001), PR positive (44.8% v. 49.4%, p<0.001), or to receive adjuvant chemotherapy (78.7% v. 81.3%, p = 0.02). The median survival of ENC patients was significantly worse than RNC patients (39 months v. 43 months, p = 0.003). By univariate analysis, improved median survival was associated with ER status (p<0.001), PR status (p<0.001), Race/ethnicity (p<0.001) and delivery of timely chemotherapy (p<0.0001). By Cox Regression analysis, ER negative status (RR 1.03; 95% CI 0.85 to 0.98, p = 0.01), African American (RR 0.94; 95% CI 0.89 to 0.99, p = 0.03), and adjuvant chemotherapy within 90 days of surgery (RR 1.40; 95% CI 1.30 to 1.50, p<0.001) remained significant predictors of survival. Conclusions: The poor outcomes observed in ENC can be attributed to recognized prognostic primary patient and tumor characteristics. However a failure in process of care remains significantly associated with poorer outcomes. Improved timing of delivery of chemotherapy could affect breast cancer mortality. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-09-12.