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.

研究目的：评估科罗拉多州早发性结直肠癌（early-onset colorectal cancer, EOCRC）的发病趋势，分析其在确诊分期、治疗手段、生存结局、地域分布及经济负担方面的差异。
材料与方法：本研究对科罗拉多州的1192例EOCRC病例进行分析，并与癌症登记处数据交叉比对，提取总生存期、治疗方式等关键变量；分别采用Cox比例风险回归模型与logistic回归模型，分析总生存期与化疗方案的相关性。
研究结果：手术治疗可使患者总生存期提升52%；II期结直肠癌患者接受化疗并未带来生存期的显著延长；城市患者接受化疗的概率是农村患者的5倍，且部分医保类型的患者接受化疗的可能性更低。
研究结论：EOCRC与传统结直肠癌（colorectal cancer, CRC）之间的差异逐渐显现，尤其是在化疗可及性方面；城乡间的化疗使用率差异提示医疗服务可及性存在潜在不平等。仍需开展进一步研究以明确该结论的普适性范围，以及医疗可及性如何影响诊疗服务。

全国范围内及科罗拉多州的早发性结直肠癌发病率均呈上升趋势。在一项多中心医疗系统的分析中，城市患者接受化疗的概率是农村患者的5倍，这提示医疗可及性存在潜在不平等。早发性结直肠癌发病率持续上升，而自20世纪90年代以来，整体结直肠癌（CRC）发病率呈下降趋势。农村人群的结直肠癌发病率更高，这一现象已引起多国研究团队的关注。早发性结直肠癌患者与农村人群均面临更高的经济毒性风险。

本研究针对科罗拉多州的多中心学术医疗系统中EOCRC人群的发病趋势展开分析，将匿名化的电子健康档案（electronic health record, EHR）数据与中央癌症登记库关联，以探索诊疗服务、人口统计学数据与生存期之间的精细关联。手术治疗可使患者总生存期提升59%；II期患者接受化疗并未带来生存期的显著改善。在针对化疗趋势的专项分析中，城市患者接受化疗的概率远超农村患者的5倍；在III期与IV期患者中，城市患者接受化疗的概率是农村患者的3倍以上。研究结果表明，农村地域是EOCRC患者生存期较差与治疗方案欠规范的独立危险因素，这一结论与结直肠癌领域的既往研究结果一致。联邦医疗保险（Medicare）类保险与化疗可及性呈近似相关，且农村患者拥有此类保险的比例更低，这提示医保类型与地域因素均可能加剧EOCRC患者的经济毒性。由于缺少完整的分期数据，本研究的纳入病例数低于初始预期。目前已提出多项旨在缩小农村医疗服务可及性差距的解决方案，但其中多数尚未经过充分验证。