Associations between micro-geographic social vulnerability and disparities in cancer incidence.

Abstract

e18523 Background: Disparities in cancer incidence and diagnosis are the result of complex physical-social-environmental interactions. Geography is one crucial lens for assessment of these disparities. The CDC’s Social Vulnerability Index (SVI) ranks micro-geographies such as Census Tracts based on social factors and can be used to identify health disparities in measures such as cancer incidence. Methods: Actual and age-adjusted expected incidence of common cancers were obtained from the New York State Cancer Registry for 2013-2017 at the Census Tract level. Data were merged with the CDC’s Overall SVI rating for 2016 at the Census Tract level. Analysis included 4,647 Census Tracts, accounting for 97.71% of New York State’s 2016 population (19,078,306 population included). For each cancer, actual and expected incidence were grouped by overall SVI percentile, then percentage deviation from expected cancer incidence was calculated. Pearson correlational test and two-tailed t-test were performed for incidence deviation of each cancer by overall SVI percentile. Results: In New York State, significant correlations between Census Tract Overall Social Vulnerability Index (SVI) percentile and percentage deviation from expected cancer incidence were found for 5 out of 6 cancers reported in the State Cancer Registry. Strong positive relationships between degree of vulnerability and deviation from expected incidence were found for Lung Cancer (R = 0.75, p < 0.001) and Colorectal Cancer (R = 0.67, p < 0.001). Strong negative relationships were found for Female Breast Cancer (R = -0.90, p < 0.001), Urinary Bladder Cancer (R = -0.76, p < 0.001), and Non-Hodgkin Lymphoma (R = -0.73, p < 0.001). A significant correlation was not found for Prostate Cancer, which demonstrated a bimodal relationship with higher excess incidence at low and high vulnerability ratings. Conclusions: There are statistically significant increases in reported incidence of Colorectal and Lung Cancers in more vulnerable Census Tracts in NY State. Paradoxically, there are significant decreases in reported incidence of Breast Cancer, Bladder Cancer, and Non-Hodgkin Lymphoma in more vulnerable Census Tracts. Further exploration of micro-geographic trends is critical to understand the extent to which these disparities are explained by true differences in cancer incidence or by variations in screening access and utilization. [Table: see text]