Abstract B128: The impact of race/ethnicity and insurance status on age-related differences in breast cancer survival
Authors: Miguel Yazmin San , Gomez Scarlett L , Murphy James D , Schwab Richard B , McDaniels-Davidson Corinne , Canchola Alison J , Molinolo Alfredo A , Nodora Jesse N , Martinez Maria E 
Published: September 2020

Background: A wealth of published data exists on factors that impact breast cancer survival, including race/ethnicity, health insurance, and other sociodemographic factors; however, there is limited research on whether associations differ by age at diagnosis. The purpose of this study was to assess risk of dying from breast cancer in older (≥ 60 years) versus younger women (&lt; 60 years) according to race/ethnicity and insurance status. Methods: From the California Cancer Registry, we identified women with a first, primary invasive breast cancer, who were ages 18 and older, diagnosed between 2005 and 2015. Multivariable Cox proportional hazards regression was used to generate hazard rate ratios (HR) and 95% confidence intervals (CI) for risk of breast cancer-specific mortality for older vs younger patients, overall and by race/ethnicity and insurance status. HRs were also calculated for race/ethnicity and insurance status, stratified by age group. Results: Of the total population (n=192,932), 94,076 (48.7%) were diagnosed under the age 60 and 98,856 (51.2%) were aged 60 and older at diagnosis. Risk of dying from breast cancer was higher in older than younger patients (HR=1.35; 95% CI, 1.29-1.40) after multivariable adjustment, which varied in magnitude by race/ethnicity (P&lt;0.0001). Larger mortality differences comparing older vs. younger patients were observed for Non-Hispanic White (NHW) (HR=1.43; 95% CI, 1.36-1.51) and Hispanic women (HR=1.37; 95% CI, 1.26-1.50), and smaller but significant differences were seen in Black (HR=1.17; 95% CI, 1.04-1.31) and Asian/Pacific Islander women (HR=1.15; 95% CI, 1.02-1.31). HRs comparing older to younger patients varied by insurance status (P&lt;0.0001) with largest mortality differences observed for privately insured women (HR=1.51; 95% CI, 1.43-1.59), followed by Medicaid/military/other public insurance (HR=1.18; 95% CI, 1.10-1.26). Black vs. NHW women had a higher risk of dying regardless of age group, with higher HRs in younger (HR=1.36; 95% CI, 1.25-1.48) than in older (HR=1.11; 95% CI, 1.01-1.22) patients. In younger women, a higher risk of breast cancer mortality was observed in those with any Medicaid/military/other public insurance (HR=1.49; 95% CI, 1.41-1.58) and in those with no insurance (HR=1.96; 95% CI, 1.65-2.32), compared to patients with private health insurance. Among older women, higher risk of mortality was seen for those with any Medicaid/military/other public insurance (HR=1.13; 95% CI, 1.06-1.21) and those with no insurance (HR=1.57; 95% CI, 1.22-2.03), compared to privately-insured patients. Conclusion: Our results provide evidence for the continued disparity in survival in Black vs White women with breast cancer, which is magnified in younger women. Moreover, lack of health insurance continues to play a role in breast cancer survival, with uninsured women having the highest risk for breast cancer death, regardless of age.

Citation Format: Yazmin San Miguel, Scarlett L Gomez, James D Murphy, Richard B Schwab, Corinne McDaniels-Davidson, Alison J Canchola, Alfredo A Molinolo, Jesse N Nodora, Maria E Martinez. The impact of race/ethnicity and insurance status on age-related differences in breast cancer survival [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B128.