Social Vulnerability as a Neighborhood-Level Determinant of Pancreatic Cancer Survivorship: A National Analysis of Veterans Affairs Patients

Abstract

Background: Veterans Affairs (VA) patients participate within the largest USA equal-access healthcare system, though still experience cancer mortality disparities by social determinants. The Social Vulnerability Index (SVI)-measuring community poverty, minority status, housing, and transportation-has delineated gradients in cancer care utilization and outcomes. We therefore assessed relationships between SVI and mortality in veterans with pancreatic ductal adenocarcinoma (PDAC).

Patients and methods: Records of patients with stage I-III PDAC diagnosed January 2005-December 2018 were abstracted from the VA Corporate Data Warehouse. Addresses were geocoded to SVI. Mann-Whitney U and chi-squared tests compared baseline characteristics. Overall survival (OS) was compared using Kaplan-Meier and multivariable Cox proportional hazards methods.

Results: A total of 1778 patients were evaluated, of which 570 (32%) underwent surgical resection. A total of 516 (29%) patients originated from census tracts in the highest SVI quartile. These patients were more likely Black (38% vs 13%), unemployed (49% vs 35%), and metropolitan-based (87% vs 76%; all p < 0.001). Over a median follow-up of 8.7 months, median OS was 9.5 months versus 10.2 months for high and low SVI groups, respectively (log-rank p = 0.03). In the resected cohort, high and low SVI groups reflected a median OS of 18.2 months versus 23.1 months, respectively (log-rank p < 0.01). High SVI remained independently associated with mortality for resected patients only (hazard ratio [HR] 1.4, p < 0.01).

Conclusions: High SVI was associated with poorer prognosis after PDAC resection. Acknowledging a need to identify mechanisms, SVI has potential use in triaging PDAC survivorship interventions in veterans.

Keywords: Cancer; Geospatial; Pancreas; Social vulnerability; Veterans.