Neighborhood Food Environment and Early-Onset Colorectal Cancer Survival

The mortality of colorectal cancer among adults < 50 years is rising, yet the role of neighborhood food environments in survival outcomes remains poorly understood.

To examine whether unhealthy food environment is associated with overall survival across early-onset colorectal cancer cohorts.

Population-based retrospective cohort study.

Connecticut, United States, 2010 to 23.

A total of 2,650 adult patients diagnosed with colorectal cancer before age 50 (early onset colorectal cancer) were identified from the Connecticut Tumor Registry.

Overall survival was defined as the time from diagnosis of early onset colorectal cancer to death from any cause. The primary exposure was a novel census tract-level Unhealthy Food Environment Index quantifying the percentage of unhealthy food retailers within a half-mile radius of each census tract.

In tertile-based comparisons, patients with early onset colorectal cancer residing in the unhealthiest food environments were younger and more likely to be female, uninsured, and from racial minority groups than those in healthier tertiles. In an unadjusted Kaplan-Meier analysis, overall survival differed across unhealthy food environment index tertiles, with the unhealthiest tertile showing the poorest survival (log-rank p = 0.03). When the unhealthy food environment index was modeled as a continuous exposure across the full cohort, residing in unhealthier census tracts was independently associated with worse overall survival (hazard ratio = 1.29, 95% CI: 1.01-1.65, p = 0.04) after adjusting for age, sex, social vulnerability, urbanicity, tumor behavior, treatment status, insurance, and number of additional primary tumors.

Cross-sectional food environment data may not reflect patient-level exposures leading up to or throughout the study period. Individual dietary intake was not measured.

Unhealthy food environments were independently associated with worse survival among patients with early-onset colorectal cancer, suggesting that the neighborhood food environment may be a modifiable structural determinant of early-onset colorectal cancer outcomes. See Video Abstract.