Abstract C35: Filipinos and blacks at a disadvantage for breast cancer survival and in-state disparities in Nevada
Authors: Pinheiro Paulo S. , Cvijetic Nevena , Kelly Rachel , Ponce Carmen , Kobetz-Kerman Erin 
Published: May 2016

Health disparities may differ by geographical area depending on contextual factors. With below average incidence, low mammography prevalence and above average mortality rates, the study of breast cancer survival outcomes is of particular interest in the state of Nevada. The health infrastructure in Southern Nevada is currently not supported by an established MD-type School of Medicine, despite the size of the Las Vegas metropolis, 2 million. We studied survival disparities for females with breast cancer in the Silver State for the period 2003-2010.

Data came from the Nevada Central Cancer Registry and cases were followed-up until Dec 31 2012 using hospital records as well as in-state and national death index linkages. We analyzed cause-specific survival rates using the actuarial method. We assessed the impact of (1) tumor-related factors: AJCC stage at diagnosis, grade of differentiation, estrogen receptors; (2) demographic factors including age, race-ethnicity (non-Hispanic Whites, non-Hispanic Blacks, Hispanics, Asian Filipino, Asian other, American Indian) , marital status; and (3) social factors such as insurance and socio-economic status on survival outcomes for breast cancer using Cox regression. For censoring times, we used the presumed-alive assumption.

A total of 11,110 cases of breast cancer cases diagnosed between 2003 and 2010 were analyzed. Survival in Northern Nevada –Reno was 88.2% after 5 years (95%CI 86.9-89.5) well within the US-SEER average of 87.0% (95%CI 86.9-87.2). Southern Nevada - Las Vegas lagged significantly behind with 83.1% (95%CI 82.2-84.0). Non-Hispanic Blacks had a 76.0% 5 year-survival (95%CI 72.6-79.4) and Filipino women 76.6% (71.3-82.0). In the multivariate analysis, Stage I, estrogen-receptor positive, and high grade of differentiation showed a lower mortality risk, while low SES and lack of insurance showed a higher mortality risk. After adjustment for all confounders, Black women showed higher mortality risk than Whites (HR 1.26 95%CI 1.06-1.50) and Southern Nevada had a 14% higher mortality risk compared to Northern Nevada for patients of the same age, race, insurance, stage at diagnosis (HR 1.14, 95%CI 1.00-1.30). The initial disadvantage for Filipino women in relation to Whites was no longer shown after adjustment for AJCC stage at diagnosis (HR 1.17, p&lt; 0.05).

Disparities according to tumor-related factors in Nevada were not different from those in the rest of the nation. However, unique disparities were observed according to demographic factors. A significant survival difference between the Northern and Southern regions of Nevada, with similar prevalence of mammography, and after adjustment for all known confounders, suggests disparities in quality of healthcare associated or not with different treatment compliance patterns. Black women are disadvantaged despite adjustment for SES, stage and insurance type, while the Filipino disadvantage is modifiable since it is caused by an unfavorable distribution of stage at diagnosis.

Citation Format: Paulo S. Pinheiro, Nevena Cvijetic, Rachel Kelly, Carmen Ponce, Erin Kobetz-Kerman. Filipinos and blacks at a disadvantage for breast cancer survival and in-state disparities in Nevada. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C35.