e12512 Background: Standard adjuvant therapy for HER2-positive female breast cancer patients who are estrogen receptor (ER) positive is chemotherapy, trastuzumab, and endocrine therapy. Some studies report disparities in receipt of adjuvant treatment based on race/ethnicity, age, and socioeconomic status (SES). This study assessed the likelihood of receipt of adjuvant chemotherapy and endocrine therapy (C+E) versus endocrine therapy (E) alone by race/ethnicity, age, and SES in the ER+/PR+/HER- and ER+/PR+/HER+ subtypes. These subtypes differ only by HER2 status. Methods: We identified 86,666 cases of stages 1-3 ER+/PR+/HER- (n=74,422) and ER+/PR+/HER+ (n=12,244) breast cancer diagnosed between January, 2000 and December, 2010 from the California Cancer Registry. Logistic regression evaluating the odds of receipt of C+E versus E alone adjusting for age, race/ethnicity, SES, grade, and year of diagnosis was conducted separately for each stage and subtype. Odds Ratios (OR) and 95% confidence intervals were reported. Results: For both subtypes in all stages, patients over age 70 were less likely to receive C+E. Stage 1 ER+/PR+/HER-: Blacks were less likely to receive C+E (OR=0.77;0.59,0.99). The opposite was true for Hispanics (OR=1.31;1.15, 1.50) and Asians (API) (OR=1.25; 1.10;1.43). Stage 1 ER+/PR+/HER+:Hispanics were more likely (OR=1.67;1.24,2.24) to receive C+E while patients in the lowest SES category were less likely to receive C+E. Stage 2: ER+/PR+/HER-:Hispanics were more likely to receive C+E (OR=1.40;1.22,1.59) Stage 2: ER+/PR+/HER+:There were no treatment differences among race or SES. Stage 3: ER+/PR+/HER-:APIs were more likely (OR=1.87;1.19,2.94) to receive C+E. Stage 3: ER+/PR+/HER+:Patients in the lowest SES category were more likely to receive C+E (OR=2.97;1.29,6.87). Conclusions: Based on this investigation of a racially diverse population, there is no striking disparity in receipt of adjuvant treatment by race/ethnicity or SES. However there are some differences among the stages and subtypes. Patients over 70 are less likely to receive chemo and endocrine therapy for the subtypes studied.
Disparities in race/ethnicity and socioeconomic status: risk of mortality of breast cancer patients in the California Cancer Registry, 2000–2010
