Chemotherapy delivery in early-onset colorectal cancer is impacted by urban versus rural settings in Colorado

<b>Aim:</b> To assess early-onset colorectal cancer (EOCRC) trends in Colorado for differences in presentation stage, therapy, survival, geography, and financial impact. <b>Materials &amp; methods:</b> A total of 1192 EOCRC cases in Colorado were analyzed and cross-referenced with registry data for key variables with overall survival and treatment modality. Cox proportional hazard regressions and logistic regressions were used to evaluate overall survival and chemotherapy relationships respectively. <b>Results:</b> Surgical treatment was associated with a 52% improvement in overall survival. Chemotherapy was not associated with increased survival in stage II disease. Urban patients were fivefold more likely to receive chemotherapy than patients from rural areas, and patients with certain insurance types were less likely to receive chemotherapy. <b>Conclusion:</b> Differences are emerging between EOCRC and traditional CRC, particularly in access to chemotherapy. The urban–rural chemotherapy rates point to potential disparity in access to care. Further research is needed to determine larger generalizability, and how access may be affecting care. Early-onset colorectal cancer incidence has been rising nationally and across Colorado. In an analysis of a multicenter health system, urban patients were fivefold more likely to receive chemotherapy, pointing to potential disparities in access. Early-onset colorectal cancer (EOCRC) incidence is rising while CRC incidence has been falling overall since the 1990s. Rural populations have higher incidence of CRC, prompting investigation by national groups. Financial toxicity rates are higher in both EOCRC and rural populations. A multicenter academic healthcare system in Colorado was analyzed for trends in the EOCRC population. Anonymized EHR data was linked with a central cancer registry to look for granular associations with medical care received, demographic data and survival. Surgical treatment was associated with a 59% improvement in overall survival. Chemotherapy was not associated with improved survival in stage II disease. In a dedicated analysis of trends in chemotherapy, urban patients were more than five-times more likely to receive chemotherapy than rural patients. Among stage III and IV disease, urban patients were more than three-times more likely to receive chemotherapy. The findings suggest that rurality is an independent risk factor for worse survival and non-ideal treatment in EOCRC, similar to findings in CRC more broadly. Medicare-style insurance was nearly associated with chemotherapy accessibility and was less likely among rural patients, suggesting insurance status and rurality may both be worsening financial toxicity in EOCRC patients. The study population was smaller than initially anticipated due to lack of complete staging data. Many solutions have been suggested to bridge the gap in rural medical access, however many of these solutions remain incompletely tested.