大规模的基于人群的登记，例如监测、流行病学和最终结果 (SEER) 登记，有助于研究罕见肿瘤，包括甲状腺髓样癌 (MTC)，但缺乏了解该疾病自然史的数据。甲状腺髓样癌协作登记处 (MTCCoRe) 是一个详尽的多机构人口统计、临床和病理数据集合。为了确定 MTCCoRe 在多大程度上代表了现实世界的 MTC 人群，我们比较了 MTCCoRe 中登记的患者与基于人群的癌症登记处登记的患者的特征。德克萨斯州癌症中心 MTCCoRe 中登记的 MTC 患者的人口统计和临床特征的比较1995年至2018年1年间，MTCCoRe中识别出416名患者，TCR中识别出329名患者，CCR中识别出2,105名患者，SEER中识别出3,820名患者。 MTCCoRe 中 20-54 岁患者的百分比为 58.0%，TCR 中为 50.2%，CCR 中为 47.2%，SEER 中为 44.8%（p < 0.0001）。大约一半的患者为女性（MTCCoRe 组为 55.9%，TCR 组为 61.4%，CCR 组为 59%，SEER 组为 57.5%（p=0.3）。西班牙裔和黑人患者的百分比在各队列中有所不同（10.1% 和 3.8%）。 MTCCoRe 患者的 TCR 分别为 23.7% 和 8.2%，CCR 患者分别为 24.8% 和 4.9%，SEER 患者分别为 15.9% 和 8.2%（p<0.001）；MTCCoRe 患者的 T 和 N 分类程度高于其他登记处的患者。 （MTCCoRe，28.6% T3-4 和 49.4% N1；TCR，12.7% 和 32.2%；CCR，18.6% 和 32.4%；SEER，24% 和 37.8%；p < 0.0001 M1 疾病患病率为 10%）。在 MTCCoRe 中，TCR 中为 11.9%，CCR 中为 14.1%，SEER 中为 9.5%（p < 0.0001）。在 MTCCoRe 中，11.4% 接受了全身治疗（TCR 中为 0.3%，CCR 中为 5.6%）。多机构登记处登记的 MTC 患者的人口统计特征与基于人口的数据库登记的患者不同，西班牙裔和黑人患者的比例较低，但未来 MTCCoRe 和其他登记处和临床试验登记工作的治疗方式的数据有所增加。应通过社区参与技术、患者利益相关者的参与以及在研究材料中纳入英语以外的语言来有意纳入代表性不足的群体，以产生更普遍的结果和结论。

Large population-based registries, such as the Surveillance, Epidemiology and End Results (SEER) Registry help in the study of rare tumors, including medullary thyroid cancer (MTC), but lack data to understand the natural history of the disease. The Medullary Thyroid Cancer Collaborative Registry (MTCCoRe) is an exhaustive multi-institutional collection of demographic, clinical, and pathologic data. To determine the extent to which MTCCoRe represents the real-world MTC population, we compared characteristics of patients enrolled in MTCCoRe with patients enrolled in population-based cancer registries.Comparison of demographic and clinical characteristics of MTC patients who were enrolled in MTCCoRe, Texas Cancer Registry (TCR), California Cancer Registry (CCR), and SEER between 1995-2018.1,416 patients were identified in MTCCoRe, 329 in TCR, 2,105 in CCR, and 3,820 in SEER. Percentages of patients 20-54 years in MTCCoRe were 58.0%, 50.2% in TCR, 47.2% in CCR, and 44.8% in SEER (p < 0.0001). About half of the patients were female (55.9% in MTCCoRe, 61.4% in TCR, 59% in CCR, and 57.5% in SEER (p=0.3). Percentages of Hispanic and Black patients differed among cohorts (10.1% and 3.8% for MTCCoRe, 23.7% and 8.2% for TCR, 24.8% and 4.9% in CCR, and 15.9% and 8.2% for SEER, respectively; p<0.001). MTCCoRe patients presented with more advanced T and N classifications than patients in the other registries (MTCCoRe, 28.6% T3-4 and 49.4% N1; TCR, 12.7% and 32.2%; CCR, 18.6% and 32.4%; and SEER, 24% and 37.8%; p < 0.0001). Prevalence of M1 disease was 10% in MTCCoRe, 11.9% in TCR, 14.1% in CCR, and 9.5% in SEER (p < 0.0001). In the MTCCoRe, 11.4% underwent systemic therapy (compared to 0.3% in TCR, 5.6% in CCR).The clinico-demographic profile of patients with MTC enrolled in a multi-institutional registry differs from those enrolled in population-based databases, with lower proportions of Hispanic and Black patients but additive data on treatment modalities. Moving forward, MTCCoRe and other registry and clinical trial enrollment efforts should intentionally include underrepresented groups via community engagement techniques, patient stakeholder involvement, and inclusion of languages other than English in study materials to yield more generalizable results and conclusions.