Neighborhood deprivation in relation to lung cancer in individuals with type 2 diabetes—A nationwide cohort study (2005–2018)

BACKGROUND: Neighborhood deprivation has been found associated with both type 2 diabetes and lung cancer. The aim of this study was to examine the potential association between neighborhood deprivation and lung cancer incidence or mortality in individuals diagnosed with type 2 diabetes. The results may identify a new risk or prognostic factor for lung cancer in this important subgroup and help develop a more contextual approach to prevention that includes neighborhood environment. METHODS AND FINDINGS: The study population included adults (n = 613,650) aged ≥ 30 years with type 2 diabetes during 2005 to 2018 in Sweden. Cox regression was used to compute hazard ratios (HRs) and 95% confidence intervals (95% CIs) for incidence or mortality of lung cancer associated with neighborhood deprivation. All models were conducted in both men and women and adjusted for individual-level characteristics (e.g. age, smoking- and alcohol-related comorbidities, sociodemographic factors). The cumulative incidence and mortality for lung cancer were 1.08% (95% CI, 1.06 to 1.11) and 0.93% (0.90 to 0.95), respectively, in the study population during the study period. Neighborhood deprivation was associated with both incidence and mortality of lung cancer in patients with type 2 diabetes independently of the individual-level characteristics. In the fully adjusted models, comparing high- with low-deprivation neighborhoods, the HRs for lung cancer incidence were 1.21 (1.10 to 1.33) in men and 1.08 (0.95 to 1.21) in women. The corresponding HRs for lung cancer mortality were 1.04 (1.00 to 1.07) in men and 0.97 (0.94 to 1.00) in women. Competing risk analyses including cardiovascular mortality attenuated the results. CONCLUSION: In this large cohort of individuals with type 2 diabetes, we found higher lung cancer incidence and mortality in patients living in areas with high neighborhood deprivation, even after adjusting for individual-level characteristics. These findings may help develop a more contextual approach that includes the neighborhood environment when allocating resources for disease prevention and care in patients with type 2 diabetes. These findings could also help inform clinical care for patients with type 2 diabetes, particularly those living in deprived neighborhoods.