Distance, Region, Insurance Status Are Risk Factors for Advanced Colon Cancer

Distance from a treating facility and insurance status are associated with an increased risk for advanced colon cancer among patients in the United States, according to a study published in JAMA Network Open.

In this cross-sectional observational study, researchers used the National Cancer Database to identify patients aged 18 years and older who received primary cancer diagnosis of colon cancer or rectal cancer, or multiple cancer diagnoses between 2010 to 2017 (n=208,085). In a secondary analysis performed to identify variables associated with advanced pathologic stage, researchers included patients who did not receive surgical intervention, received neoadjuvant therapy, or received surgical intervention on multiple sites during their index operation (n=236,309).

Patients who traveled more than 20.2 kilometers (km) from their medical facility had increasing odds of presenting with advanced clinical-stage disease compared with those who lived within 20.0 km from their medical facility (20.2 to 80.0 km [odds ratio (OR), 1.11; 95% CI, 1.09-1.14); 81.0 to 400.0 km (OR, 1.39; 95% CI, 1.34-1.44), and at least 400.0 km (OR, 1.78, 1.62-1.94). The secondary analysis, adjusting for all variables, showed that having no insurance (OR, 1.33; 95% CI, 1.27-1.39) or having only Medicaid (OR, 1.22; 95% CI, 1.18-1.27) was associated with advanced pathologic stage.

The primary limitation of the study is the potential bias created by calculating income and distance by zip code, instead of by patient level.

“The findings of this study suggest that distance from the treating facility and insurance status are risk factors for the diagnosis of advanced-stage colon cancer among patients in the US,” the study authors concluded. “These findings are important as more rural hospitals are closing and care becomes more regionalized at high-volume centers. Interventions to provide transportation may be useful in the Mountain, Central, and Northeast regions, where patients living far from hospitals have greater risk for diagnosis of advanced stage disease.”