在转移性结直肠癌 (mCRC) 患者中，关于不同生物标志物检测及其与全国范围内临床结果的关联的数据有限。探索测试与总生存期 (OS) 的关联。这项队列研究于 2022 年 11 月至 2024 年 3 月期间进行，纳入了 2010 年 1 月 1 日至 2017 年 12 月 31 日期间被诊断患有转移性结直肠癌的患者。该研究从国家癌症数据库，美国医院的癌症登记处。转移性结直肠癌患者和生物标志物检测的可用信息均包括在内。根据患者是否完成 MSI 或 KRAS 测试对患者进行分类。人口统计和社会经济因素，例如年龄、种族、民族、居住地区的教育水平、家庭收入中位数、保险类型、居住地区、设施类型和设施位置进行了评估。主要结果是诊断日期和第一疗程治疗日期之间的 MSI 和 KRAS 测试。使用单变量和多变量逻辑回归来确定 MSI 和 KRAS 测试中的相关因素。还评估了 OS 结果。 在 41061 名患者中（22 362 名男性 [54.5%]；平均 [SD] 年龄，62.3 [10.1] 岁；17.3% 为黑人，78.0% 为白人，4.7% 为白人）其他种族的个体（其中 6.5% 为西班牙裔，93.5% 为非西班牙裔），28.8% 接受了 KRAS 检测，43.7% 接受了 MSI 检测。很大一部分患者拥有医疗保险（43.6％），在综合社区癌症计划中接受治疗（40.5％），并且居住在教育水平较低的地区（51.3％）。与 MSI 检测可能性较低相关的因素包括年龄 70 至 79 岁（相对风险 [RR]，0.70；95% CI，0.66-0.74；P < .001）、在社区癌症计划中接受治疗（RR，0.74；95% CI，0.66-0.74；P< .001）。 95% CI，0.70-0.79；P < .001），农村居民（RR，0.80；95% CI，0.69-0.92；P < .001），居住地区教育水平较低（RR，0.84；95% CI） ，0.79-0.89；P < .001），以及在东南中心设施进行的治疗（RR，0.67；95% CI，0.61-0.73；P < .001）。 KRAS 测试也观察到类似的模式。生存分析显示，接受 MSI 检测的患者 OS 略有改善（风险比，0.93；95% CI，0.91-0.96；P < .001）。生存分析的中位 (IQR) 随访时间为 13.96 (3.71-29.34) 个月。这项针对 mCRC 患者的队列研究发现，年龄较大、社区环境治疗、居住地教育水平较低以及治疗地点东南中部设施与 MSI 和 KRAS 检测的可能性降低有关。强调生物标志物测试中基于社会人口统计学的差异可以为制定促进癌症护理公平并改善服务不足人群的结果的策略提供信息。

Among patients with metastatic colorectal cancer (mCRC), data are limited on disparate biomarker testing and its association with clinical outcomes on a national scale.To evaluate the socioeconomic and demographic inequities in microsatellite instability (MSI) and KRAS biomarker testing among patients with mCRC and to explore the association of testing with overall survival (OS).This cohort study, conducted between November 2022 and March 2024, included patients who were diagnosed with mCRC between January 1, 2010, and December 31, 2017. The study obtained data from the National Cancer Database, a hospital-based cancer registry in the US. Patients with mCRC and available information on biomarker testing were included. Patients were classified based on whether they completed or did not complete MSI or KRAS tests.Demographic and socioeconomic factors, such as age, race, ethnicity, educational level in area of residence, median household income, insurance type, area of residence, facility type, and facility location were evaluated.The main outcomes were MSI and KRAS testing between the date of diagnosis and the date of first-course therapy. Univariable and multivariable logistic regressions were used to identify the relevant factors in MSI and KRAS testing. The OS outcomes were also evaluated.Among the 41 061 patients included (22 362 males [54.5%]; mean [SD] age, 62.3 [10.1] years; 17.3% identified as Black individuals, 78.0% as White individuals, 4.7% as individuals of other race, with 6.5% Hispanic or 93.5% non-Hispanic ethnicity), 28.8% underwent KRAS testing and 43.7% received MSI testing. A significant proportion of patients had Medicare insurance (43.6%), received treatment at a comprehensive community cancer program (40.5%), and lived in an area with lower educational level (51.3%). Factors associated with a lower likelihood of MSI testing included age of 70 to 79 years (relative risk [RR], 0.70; 95% CI, 0.66-0.74; P < .001), treatment at a community cancer program (RR, 0.74; 95% CI, 0.70-0.79; P < .001), rural residency (RR, 0.80; 95% CI, 0.69-0.92; P < .001), lower educational level in area of residence (RR, 0.84; 95% CI, 0.79-0.89; P < .001), and treatment at East South Central facilities (RR, 0.67; 95% CI, 0.61-0.73; P < .001). Similar patterns were observed for KRAS testing. Survival analysis showed modest OS improvement in patients with MSI testing (hazard ratio, 0.93; 95% CI, 0.91-0.96; P < .001). The median (IQR) follow-up time for the survival analysis was 13.96 (3.71-29.34) months.This cohort study of patients with mCRC found that older age, community-setting treatment, lower educational level in area of residence, and treatment at East South Central facilities were associated with a reduced likelihood of MSI and KRAS testing. Highlighting the sociodemographic-based disparities in biomarker testing can inform the development of strategies that promote equity in cancer care and improve outcomes for underserved populations.