Differential frequency of breast cancer molecular profiling by socioeconomic status in San Diego, California.

Abstract

e21061 Background: Previous reports demonstrate inferior outcomes for cancer patients of low socioeconomic status (SES). The development of breast tumor molecular profiling has optimized anticancer therapy but its effect on outcome for those with barriers to care is unknown. Methods: Breast cancer patients appropriate for OncotypeDX testing (Genomic Health, Inc) were identified from The Scripps Health Tumor Registry. High SES was defined as patients residing in zip codes with a median household income in the top quartile for the county according to the San Diego Association of Governments. Low SES was defined as patients residing in zip codes with median income in the bottom quartile or with Medical as primary insurance. The frequency of OncotypeDX testing, result, therapy prescribed, relapse and cancer specific death rates are reported. Statistical analysis was performed by unpaired t-test; p values≤0.05 were considered significant. Results: 2,192 early-stage breast cancer patients were identified; 167 met criteria. Patients were younger (p<0.0001) and a lower rate of OncotypeDX testing was noted in the low SES group (p=0.028); no difference in stage was observed. All patients were prescribed anti hormone therapy but the low SES group received chemotherapy more frequently (p=0.0075). No difference in relapse rate and no deaths attributable to cancer were noted. Conclusions: We observed a lower rate of OncotypeDX use in the low SES cohort. While the cause is unclear, the higher rate of chemotherapy use in this group may represent overtreatment. Determining a survival impact attributable to this difference requires longer follow-up. Our data demonstrate the need for prospective analysis of tumor profiling use in low SES individuals to ensure early stage breast cancer patients receive optimal therapy. [Table: see text]