Association between socioeconomic factors and utilization of next-generation sequencing in metastatic breast cancer.

e13700 Background: Targeted therapies such as PI3K inhibitors have revolutionized the treatment of patients with metastatic breast cancer (MBC). Their selective use is enabled by next-generation sequencing (NGS) approaches, which help identify actionable tumor alterations. There may be socioeconomic disparities in NGS testing and NGS-guided treatment selection. This study aimed to investigate the role of socioeconomic status (SES) (race and area deprivation index ADI) among patients with MBC undergoing NGS. Methods: Our retrospective study included 418 adult patients (pts) with MBC treated at the Magee Women’s Cancer Center in Pittsburgh, PA between September 2016 and December 2022. Demographic information, including race and ADI, clinicopathologic information, and NGS results were collected. ADI based on zip code was derived utilizing Neighborhood Atlas. Scores range from 0-10 (higher score = higher deprivation), representing the census-based ranking of the ZIP code at the state level based on the composite of several factors, including income, education, employment, and housing quality. Descriptive statistics, chi-squared, and independent sample t tests were used. Multivariate logistic regression analysis was done to evaluate potential associations with receipt of NGS and NGS-directed therapy. Results: 89% of pts were non-Hispanic white (NHW); 11% were non-Hispanic black (NHB). A greater proportion of NHB pts were from higher ADI (6-10) neighborhoods (p=0.00001), suggesting lower SES. NHW pts were more likely to have hormone receptor (HR)+/human epidermal growth factor receptor (HER)2- tumors compared with NHB pts (p=0.022). 219 (52.4%) total pts had NGS tumor testing performed: 53% of NHW and 47.8% of NHB pts (p=0.511). 55.1% (102/185) of pts living in higher SES neighborhoods (ADI 1-5) and 50.2% (117/233) living in lower SES neighborhoods (ADI 6-10) received NGS testing (p=0.317). Of the 219 pts who got NGS testing, 62.6% (137) had a clinically actionable alteration identified, and of those, 46% (63) received corresponding targeted therapy. Of the 63 pts who received NGS-guided therapy, 88.9% were NHW and 11.1% were NHB (p=0.849), and 50.8% were from neighborhoods with ADI 1-5 and 49.2% were from neighborhoods with ADI 6-10 (p=0.571). In multivariate analysis including race, ADI, insurance status, year of MBC diagnosis, and tumor subtype, only tumor subtype (non-HR+/HER2- tumors) was significantly associated with a lower likelihood of both receiving NGS testing (p=0.032) and receiving NGS-directed therapy (p=0.001). Conclusions: There was a higher numerical rate of NGS testing and NGS-guided therapy initiation in NHW pts and pts from lower ADI (1-5 vs. 6-10) neighborhoods, but this did not reach statistical significance. Overall, in this single institution cohort limited by small numbers, there were no differences in NGS tumor testing based on race and SES.