Background

There are currently no evidence-based guidelines for the management of enlarged mediastinal lymph nodes found on lung cancer screening (LCS) CT scans.

Purpose

To assess the frequency and clinical significance of enlarged mediastinal lymph nodes on the initial LCS CT scans in National Lung Screening Trial (NLST) participants.

Materials and Methods

A retrospective review of the NLST database identified all CT trial participants with at least one enlarged (≥1.0 cm) mediastinal lymph node identified by site readers on initial CT scans. Each study was reviewed independently by two thoracic radiologists to measure the two largest nodes and to record morphologic characteristics. Scans with extensively calcified mediastinal lymph nodes or nodes measuring less than 1 cm were excluded. Frequency and time to lung cancer diagnosis, lung cancer stage, and histologic findings were compared between NLST participants with and without lymphadenopathy.

Results

Of the 26 722 NLST participants, 422 (1.6%) had enlarged noncalcified mediastinal lymph nodes on the initial LCS CT scan. Mediastinal lymphadenopathy was associated with an increase in lung cancer cases (72 of 422 participants [17.1%; 95% CI: 13.6, 21.0] vs 1017 of 26 300 [3.9%; 95% CI: 3.6, 4.1]; P < .001), earlier diagnosis (restricted mean survival time ± standard error, 2285 days ± 44 vs 2611 days ± 2; P < .001), the presence of lung nodules (P < .001), advanced stage at presentation (22 of 72 participants [31%] with cancer at stage IIIA vs 410 of 1017 [40.3%] at stage IA; P < .001), and increased mortality (P < .001). The majority of participants with lung cancers in the LCS group with mediastinal lymphadenopathy were detected at initial LCS CT (50 of 422 participants [11.8%; 95% CI: 8.9, 15.3] vs T1–T7, 22 of 422 [5.3%; 95% CI: 3.3, 7.8]; P < .001). There was no association between mediastinal lymphadenopathy and lung cancer histologic findings, CT appearance, or location of lung nodules (P > .05 based on unadjusted pairwise association analyses).

Conclusion

Noncalcified mediastinal lymphadenopathy in the low-dose lung cancer screening study sample was associated with an increase in lung cancer, an earlier diagnosis, more advanced-stage disease, and increased mortality. More aggressive treatment of these patients appears warranted.

© RSNA, 2021

Online supplemental material is available for this article.

See also the editorials by McLoud and by Mascalchi and Zompatori in this issue.

中文翻译：

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国家肺癌筛查试验 (NLST) 中的纵隔淋巴结肿大与间期肺癌有关

背景

目前尚无针对肺癌筛查 (LCS) CT 扫描发现的纵隔肿大淋巴结管理的循证指南。

目的

评估国家肺筛查试验 (NLST) 参与者初次 LCS CT 扫描时纵隔淋巴结肿大的频率和临床意义。

材料和方法

对 NLST 数据库的回顾性审查确定了所有 CT 试验参与者，在初始 CT 扫描中，站点读者发现至少有一个扩大 (≥1.0 cm) 纵隔淋巴结。每项研究均由两名胸部放射科医师独立审查，以测量两个最大的淋巴结并记录形态学特征。排除了具有广泛钙化纵隔淋巴结或测量小于 1 cm 的淋巴结的扫描。在有和没有淋巴结病的 NLST 参与者之间比较了肺癌诊断的频率和时间、肺癌分期和组织学结果。

结果

在 26 722 名 NLST 参与者中，422 名 (1.6%) 在最初的 LCS CT 扫描中出现非钙化纵隔淋巴结肿大。纵隔淋巴结肿大与肺癌病例增加相关（422 名参与者中的 72 名 [17.1%；95% CI：13.6, 21.0] vs 26 300 名中的 1017 名 [3.9%；95% CI：3.6, 4.1]；P < .001 )、早期诊断（限制平均生存时间 ± 标准误差，2285 天 ± 44 天 vs 2611 天 ± 2；P < .001），肺结节的存在 ( P < .001)，就诊时处于晚期（72 名参与者中的 22 名） [31%] 在 IIIA 期患有癌症，而 IA 期 1017 人中有 410 人 [40.3%]；P < .001），死亡率增加（P< .001)。LCS 组中大多数患有纵隔淋巴结肿大的肺癌参与者在初始 LCS CT 时被检测到（422 名参与者中的 50 名 [11.8%；95% CI：8.9, 15.3] vs T1-T7，422 名中的 22 名 [5.3%；95 % CI：3.3, 7.8]；P < .001)。纵隔淋巴结肿大与肺癌组织学发现、CT 表现或肺结节位置之间没有关联（P > .05，基于未经调整的成对关联分析）。

结论

低剂量肺癌筛查研究样本中的非钙化纵隔淋巴结肿大与肺癌增加、早期诊断、更晚期疾病和死亡率增加有关。对这些患者进行更积极的治疗似乎是必要的。

© 北美放射学会，2021

本文提供在线补充材料。

另请参阅本期 McLoud 以及 Mascalchi 和 Zompatori 的社论。