Racial/ethnic disparities in estrogen and progesterone receptor phenotype and survival outcomes.

54 Background: The incidence of estrogen receptor (ER) and progesterone receptor (PR) phenotypes varies among different racial/ethnic groups. However, the prognostic significance of specific ER/PR phenotypes on survival in racial/ethnic groups including Asians has not been reported. Methods: The Surveillance Epidemiology and End Results (SEER) database was used to identify invasive breast cancer cases from 1988 to 2009. Groups included were: “Non-Hispanic Whites (NHW)”, “Blacks”, “Filipinos”, “Chinese”, “Japanese”, “Koreans”, “Vietnamese”, and “Asian Indian/Pakistanis (AIP)”. Cases were grouped according to ER/PR phenotype (ER+/PR+, ER-/PR-, ER+/PR-, ER-/PR+). The Kruskall-Wallis test, and the Z test were employed to examine for differences between racial/ethnic groups. Multivariate Cox proportional analyses were used to establish the weight of the age adjusted ER/PR phenotype on the prognostic significance contributing to survival. Results: In comparison to NHW, ER+/PR+ status was associated with poor ou...