Defining the Role of Social Vulnerability in Treatment and Survival in Localized Colon Cancer: A Retrospective Cohort Study.

Objective: To determine whether variations in Social Vulnerability Index (SVI) are associated with disparities in colon cancer surgery and mortality.

Summary Background Data: Colon cancer mortality is influenced by health care access, which is affected by individual and community-level factors. Prior studies have not used the SVI to compare surgical access and survival in localized colon cancer patients. Further, it is unclear if those above 65 years are more vulnerable to variations in SVI.

Methods: We queried the Texas and California Cancer Registries from 2004-2017 to identify patients with localized colonic adenocarcinoma and categorized patients into <65 and ≥65 years. Our outcomes were survival and access to surgical intervention. The independent variable was census tract social vulnerability index, with higher scores indicating more social vulnerability. We used multivariable logistic regression and Cox proportional hazards for analysis.

Results: We included 73,923 patients with a mean age of 68.6 years (SD 13.0), mean SVI of 47.2 (SD 27.6), and 51.1% male. After adjustment, increasing SVI was associated with reduced odds of undergoing surgery (OR 0.996; 95% CI 0.995-0.997; P < 0.0001 and increased mortality (HR 1.002; 95% CI 1.001-1.002; P < 0.0001). Patients < 65 years were more sensitive to variation in SVI.

Conclusions: Increased social vulnerability was associated with reduced odds of receiving surgery for early-stage colon cancer as well as increased mortality. These findings amplify the need for policy changes at the local, state, and federal level to address community-level vulnerability to improve access to surgical care and reduce mortality.