Abstract
PURPOSE: Neighborhood environments may influence cancer risk. Average population effect estimates might mask differential effects by socioeconomic position. Improving neighborhood environments could inadvertently widen health inequalities if important differences are overlooked. METHODS: Using linked records of hospital admissions in UK Biobank, we assessed associations between admission with a primary diagnosis of cancer (any/breast/colorectal), and exposure to neighborhood greenspace, physical activity facilities, and takeaway food stores, and whether household income and area deprivation modify these associations. We used adjusted Cox proportional hazards models, and estimated relative excess risks due to interaction (RERI) to assess effect modification. RESULTS: Associations between neighborhood exposures and cancer-related hospitalizations were weak to null overall, but with some evidence of effect modification. Most notably, more greenspace near home was associated with 16% lower hazard of cancer-related hospital admission in deprived areas (95% CI 2-29%). This was further pronounced for people in low-income households in deprived areas, and for breast cancer. CONCLUSION: In deprived neighborhoods, increasing the amount of greenspace may help reduce cancer-related hospitalizations. Examining effect modification by multiple socioeconomic indicators can yield greater insight into how social and environmental factors interact to influence cancer incidence. This may help avoid perpetuating cancer inequalities when designing neighborhood environment interventions.