Income inequalities, tumor stage at diagnosis, and treatment in patients with non‐small cell lung cancer: A population‐based study in the Netherlands

This study investigated the association between income, tumor stage, and treatment in non‐small cell lung cancer (NSCLC) patients, stratified by Eastern Cooperative Oncology Group performance status (ECOG‐PS). Patients diagnosed with NSCLC between 2017 and 2022 were selected from the Netherlands Cancer Registry ( N = 71,025). Median household income at postal code level served as a proxy for income. Logistic regression was used to investigate the association between income, tumor stage at diagnoses and treatment. All analyses were stratified by ECOG‐PS (PS0‐1 vs. PS2+). Patients with an intermediate or higher income were more likely to be diagnosed with a stage IV tumor compared with those with a lower income. This was seen in patients with PS0‐1 (odds ratio [OR] intermediate_vs_lower : 1.13 [95% confidence interval [95% CI]: 1.08–1.18], OR higher_vs_lower : 1.23 [1.18–1.29]) and PS2+ (OR intermediate_vs_lower : 1.19 [1.11–1.27], OR higher_vs_lower : 1.30 [1.19–1.41]). In patients with PS0‐1 and a stage II or III tumor, those with an intermediate or higher income more often received a cancer treatment (stage II OR intermediate_vs_lower : 1.47 [1.09–1.99], OR higher_vs_lower : 1.54 [1.13–2.11], stage III OR intermediate_vs_lower : 1.20 [1.03–1.40], OR higher_vs_lower : 1.30 [1.09–1.55]). In patients with PS0‐1 and a stage IV tumor, those with an intermediate or higher income more often received immunotherapy (OR intermediate_vs_lower : 1.10 [1.02–1.19], OR intermediate_vs_lower : 1.30 [1.20–1.41]) and systemic treatment (OR intermediate_vs_lower : 1.29 [1.20–1.39], OR higher_vs_lower : 1.50 [1.37–1.63]). The latter was also found in patients with PS2+ (OR intermediate_vs_lower : 1.22 [1.08–1.38], OR higher_vs_lower : 1.42 [1.23–1.64]). We thereby showed that even in a country with a universal healthcare system, large differences can be seen in the treatments of NSCLC patients according to income.