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

Abstract

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.

Keywords: Area deprivation index; Breast cancer; Healthcare disparities.

Fig. 1

Study design. CONSORT diagram. DCIS ductal carcinoma in situ, ADI area deprivation index, high ADI ≥ 60 most disadvantaged areas, low ADI < 60 less disadvantaged areas

Fig. 2

The geographic distribution of the area distribution index (ADI) across WNY Adapted from [Ref. 17]

Fig. 3

Frequency of somatic mutations by ADI. TP53 (13% vs. 23%, P = 0.67), BRCA1 (0% vs. 8%, P = 0.54), BRCA2 (0% vs. 4%, P = 1.00), PIK3CA (7% vs. 19%, P = 0.38), ATM (13% vs. 0%, P = 0.13), ESR1 (13% vs. 27%, P = 0.43), ERBB2 (formerly HER2) (13% vs. 7.7%, P = 0.63), ADI < 60 vs. ADI ≥ 60, respectively. ADI area deprivation index, TP53 tumor protein P53, BRCA1 breast cancer gene 1, BRCA2 breast cancer gene 2, PIK3CA phosphatidylinositol 3-kinase, ATM Ataxia-telangiectasia mutated, ESR1 estrogen receptor 1, ERBB2 Erb-b2 receptor tyrosine kinase 2

Fig. 4

Overall survival by ADI. ADI area deprivation index

Fig. 5

Forest plot: multivariable analyses of demographic and clinical characteristics associated with survival in breast cancer patients. ECOG Eastern Cooperative Oncology Group, HR⁺ hormonal positive (estrogen or progesterone positive), HER2⁺ human epidermal growth factor receptor 2 positive, TNBC triple-negative breast cancer, late stage stage IV breast cancer, early stage IIII breast cancer, ADI area deprivation index