Abstract A78: Atlas of disparities in cancer survival in California: An intersectional approach
Authors: Ellis Elizabeth , Gomez Scarlett L. 
Published: March 2017

The burden of cancer on the diverse U.S. population is not equal. Enduring disparities in survival persist by social determinants of health (SDOH) including race/ethnicity, nativity, individual and contextual socioeconomic status (SES), and marital status. To accurately target cancer control initiatives to patients with the greatest need, it is vital to know where disparities in survival occur. The cancer survival atlas aims to systematically identify disparities in cancer survival in the state of California, applying an intersectional approach to examine disparities jointly by sex and SDOH factors including race/ethnicity, nativity, health insurance, marital status, and neighborhood SES. The atlas will provide the necessary epidemiological underpinning for future initiatives focused on improving outcomes in disadvantaged and under-served populations.

Statewide population-based cancer registry data, enhanced with complete nativity and neighborhood characteristics, was used to produce cancer-specific survival at 1-, 3-, 5- and 10-years for all patients diagnosed between the year 2000 and 2013 with one of the five most common cancers in the state (breast, prostate, lung, colorectal and melanoma). Population groups were defined by sex, age, marital status, race/ethnicity (non-Hispanic White, Hispanic, Black, and Asian American & Pacific Islander (AAPI) ethnic groups), nativity, health insurance, and neighborhood SES. Neighborhood SES was assigned to cases based on residential block group, based on principal components analyses derived indices from 2000 Census or 2007-2011 American Community Survey data, and categorized according to statewide quintiles. Age and stage-adjusted survival probabilities were estimated, then multivariable Cox Proportional Hazard models were used to investigate the relative contribution of factors associated with survival and to adjust for confounders.

We found considerable socioeconomic and racial/ethnic disparities in survival for all five cancer sites examined, with the largest disparities seen for cancers with a good prognosis (breast, prostate, melanoma), and by health insurance status of all of the SDOH factors. For breast cancer, women residing in neighborhoods with the lowest SES quintile had significantly poorer cancer-specific survival than women in the highest SES quintile (hazard ratio (HR) = 1.53 (95% CI 1.47-1.61), adjusting for stage, health insurance, race/ethnicity). The largest racial/ethnic disparities were also seen in breast cancer. Non-Hispanic Black women had the lowest survival (HR = 1.50 (95% CI 1.44-1.56)), and AAPI women the highest (HR = 0.85 (95% CI 0.81-0.89)) compared to Non-Hispanic White women. Differences in survival by health insurance status were also evident for all five cancers. For melanoma, survival was substantially lower among men with no health insurance (HR = 1.89 (95% CI 1.57-2.26)) and among men with public, military or Medicaid insurance (HR = 1.40 (95% CI 1.29-1.52)) compared to men with private insurance. Disparities in survival by health insurance status were present across all socioeconomic and racial/ethnic groups.

Disparities in survival among groups defined by SDOH factors in California are substantial. These results will serve as a resource for the targeting and development of interventions, such as early diagnosis initiatives, to address the needs of specific population groups in California.

Citation Format: Elizabeth Ellis, Scarlett L. Gomez. Atlas of disparities in cancer survival in California: An intersectional approach. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr A78.