106 Background: Racial/ethnic disparities in breast cancer mortality have been described. Geographic variation in breast cancer mortality has also been observed. The purpose of this study is to determine if there are racial disparities in breast cancer survival among eight regions in California, the most populous state in the U.S. Methods: Of 245,701 cases of first primary female invasive breast cancer from the California Cancer Registry (CCR) diagnosed in 2000-2011, we identified 143,184 with complete data. The regions of California were classified as North, Sacramento, San Francisco and Bay Area (SFBA), Central Valley, Tri-County, Desert Sierra, Los Angeles (LA), and San Diego/Orange. Cox Proportional Hazards was conducted to assess risk of mortality of African Americans, Hispanics, Asian/Pacific Islanders, and American Indians when compared with whites. The region X race interaction was tested. Analyses were adjusted for year of diagnosis, stage at diagnosis, grade, age, and socioeconomic status. Hazard ratios and 95% confidence intervals were reported. Results: The region X race/ethnicity interaction was statistically significant so separate models were fitted for each region. Blacks has increased mortality in SFBA (HR = 1.36; 1.20, 1.56), LA (HR = 1.37; 1.24, 1.51) and San Diego/Orange (HR = 1.31; 1.07, 1.60). American Indians had an increased risk of mortality in the Tri-County (HR = 3.90; 1.73, 8.78) and San Diego (HR = 1.93; 1.04, 3.64) regions. Hispanics had a reduced risk mortality only in the Tri County region (HR = 0.71; 0.55, 0.93). Asians had a lower risk of mortality in San Diego/Orange (HR = 0.81; 0.70. 0.94) and LA (HR = 0.78; 0.70; 0.87). Race was not a statistically significant factor for risk of mortality in the North, Sacramento, Central Valley, and Desert Sierra regions. Conclusions: Racial disparities in breast cancer mortality California vary by region and appear to be more prevalent in large urban areas.
Literature review of data-based models for identification of factors associated with racial disparities in breast cancer mortality
