Area deprivation index and breast cancer outcomes among patients in Western New York.

Background: Several studies have shown that residing in regions with high area deprivation index (ADI) is associated with worse outcomes. We evaluated associations between ADI and breast cancer (BC) outcomes among patients in Western New York (WNY), a region that includes multiple underserved areas.

Methods: This retrospective, single-institution study analyzed data from 404 BC patients diagnosed between 2014 and 2018. Demographic and clinicopathological data were abstracted. Data were compared between high (≥ 60) and low (< 60) ADI groups, reflective of high and low levels of socioeconomic disadvantage, respectively. The primary objective was overall survival (OS) by ADI. Secondary objectives included assessment of recurrence free survival (RFS) or time to next treatment (TNT) by ADI and frequency of germline and somatic testing.

Results: Over half of the patients (59%) resided in ADI ≥ 60. 77% of patients had stage I-III BC and 23% had de novo metastatic BC. Patients in ADI ≥ 60 had a lower 5-year OS rate (73%) than those in ADI < 60 (84%) (95%CI: 67.5-79.7, P = 0.05). In multivariable analysis, similar trend was observed but was not statistically significant (HR 1.56, 95%CI: 0.98-2.46, P = 0.058). There were no differences in TNT or RFS by ADI. Germline testing was performed less frequently (33%) in ADI ≥ 60 than ADI < 60 group (45%) (P = 0.04) for patients with stage I-III BC, while no difference observed for stage IV patients. Finally, prevalence of somatic mutations in TP53, PIK3CA, and ESR1 were higher in ADI ≥ 60.

Conclusions: We observed a trend towards worse OS in areas with high ADI, though not statistically significant. The incidence of germline testing was lower in high ADI compared to low ADI regions.