Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.
Section of Thoracic Surgery, Department of Surgery, University of Manitoba, Health Sciences Centre, Winnipeg, MB, Canada.
Chest. 2021 Jun;159(6):2470-2476. doi: 10.1016/j.chest.2020.12.050. Epub 2021 Jan 9.
Staging guidelines for lung cancer recommend endobronchial ultrasound (EBUS) and systematic biopsy of at least three mediastinal lymph node (LN) stations for accurate staging. A four-point ultrasonographic score (Canada Lymph Node Score [CLNS]) was developed to determine the probability of malignancy in each LN. A LN with a CLNS of < 2 is considered low probability for malignancy. We hypothesized that, in patients with cN0 non-small cell lung cancer, LNs with CLNS of < 2 may not require routine biopsy because they represent true node-negative disease.
Do LNs considered triple normal on CT scanning, PET scanning, and CLNS evaluation require routine biopsy?
LNs were evaluated for ultrasonographic features at the time of EBUS and the CLNS was applied. Triple-normal LNs were defined as cN0 on CT scanning (short axis, < 1 cm), PET scanning (no hypermetabolic activity), and EBUS (CLNS, < 2). Specificity and negative predictive value (NPV) were calculated against the gold standard pathologic diagnosis from surgically excised specimens.
In total, 143 LNs from 57 cN0 patients were assessed. Triple-normal LNs showed a specificity and NPV of 60% (95% CI, 51.2%-68.3%) and 93.1% (95% CI, 85.6%-97.4%), respectively. After pathologic assessment, only 5.6% (n = 8/143) of triple-normal nodes were proven to be malignant.
At the time of staging for lung cancer, combining CT scanning, PET scanning, and CLNS criteria can identify triple-normal LNs that have a high NPV for malignancy. This raises the question of whether triple-normal LNs require routine sampling during EBUS and transbronchial needle aspiration. A prospective trial is required to confirm these findings.
肺癌分期指南建议对至少三个纵隔淋巴结（LN）站进行支气管内超声（EBUS）和系统活检，以进行准确的分期。为了确定每个 LN 的恶性肿瘤概率，开发了一种四点超声评分（加拿大淋巴结评分[CLNS]）。CLNS<2 的 LN 被认为恶性肿瘤的概率较低。我们假设，在 cN0 非小细胞肺癌患者中，CLNS<2 的 LN 可能不需要常规活检，因为它们代表真正的淋巴结阴性疾病。
在 CT 扫描、PET 扫描和 CLNS 评估中被认为是三联正常的 LN 是否需要常规活检？
在 EBUS 时评估 LN 的超声特征，并应用 CLNS。三联正常 LN 定义为 CT 扫描（短轴，<1cm）、PET 扫描（无高代谢活性）和 EBUS（CLNS，<2）的 cN0。特异性和阴性预测值（NPV）是根据手术切除标本的金标准病理诊断计算得出的。
共评估了 57 例 cN0 患者的 143 个 LN。三联正常 LN 的特异性和 NPV 分别为 60%（95%CI，51.2%-68.3%）和 93.1%（95%CI，85.6%-97.4%）。在病理评估后，只有 5.6%（n=8/143）的三联正常节点被证实为恶性。
在肺癌分期时，结合 CT 扫描、PET 扫描和 CLNS 标准，可以识别出具有高 NPV 恶性肿瘤的三联正常 LN。这就提出了一个问题，即在 EBUS 和经支气管针吸活检期间，三联正常 LN 是否需要常规取样。需要进行前瞻性试验来证实这些发现。
