Socioeconomic differences among patients with stage I-III colon cancer: Detection, treatment and relative survival

Colon cancer is a significant public health concern. Several risk factors for colon cancer are strongly associated with socioeconomic position (SEP). This study investigates associations between SEP and screening versus clinical detection, treatment characteristics, and relative survival. Patients with stage I-III colon cancer diagnosed between 2015 and 2023 were selected from the Netherlands Cancer Registry. SEP was based on household income at postal code level. Associations between SEP and screening versus clinical detection and treatment characteristics were assessed using multivariable logistic regression analyses. Crude 5-year relative survival by SEP was calculated, and relative excess risks of death were assessed using a multivariable generalized linear model. The total study population consisted of 62,412 patients. Most prominently, compared to patients with lower SEP, patients with intermediate or higher SEP were more often diagnosed through screening (23% vs. 31% and 33%, p <.0001), more often received adjuvant chemotherapy in stage III (53% vs. 64% and 68%, p <.0001), and less often had an adverse hospital course (54% vs. 47% and 44%, p <.0001). Crude 5-year relative survival was 86.0% for lower, 87.5% for intermediate, and 88.7% for higher SEP (intermediate versus lower SEP: adjusted RER 0.97, 95% CI 0.90-1.03; higher versus lower SEP: adjusted RER 0.89, 95% CI 0.83-0.95). Patients with intermediate or higher SEP were more often diagnosed through screening and had several favorable treatment characteristics compared to patients with lower SEP. For higher versus lower SEP, this translated into a small survival advantage, even after adjustment for patient, tumor, and treatment characteristics.