Occult lymph node metastasis in radiologic stage I non‐small cell lung cancer: The role of endobronchial ultrasound

• Published in: The clinical respiratory journal 2021-06, Vol.15 (6), p.676-682
• Main Authors: Kukhon, Faeq R., Lan, Xinyue, Helgeson, Scott A., Arunthari, Vichaya, Fernandez‐Bussy, Sebastian, Patel, Neal M.
• Format: Article
• Language: English
• Subjects: Biopsy; EBUS‐TBNA; Endobronchial ultrasound; Lung cancer; Lymphatic system; Metastasis; NSCLC; occult metastasis; staging; Tumors; Ultrasonic imaging
• ISSN: 1752-6981; 1752-699X
• DOI: 10.1111/crj.13344

Rationale The use of endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) is currently recommended for staging non‐small cell lung cancer (NSCLC) in centrally located tumors, tumors >3 cm, or with radiologic evidence of lymph node (LN) metastasis. Current guidelines do not recommend staging EBUS‐TBNA in patients with stage I NSCLC who do not have any of the aforementioned conditions. Objective We hypothesize that using EBUS‐TBNA is useful for detecting occult metastasis in radiologic stage I NSCLC. Methods In this single‐center, retrospective study, charts of patients ≥18 years old who underwent staging EBUS‐TBNA from January 2005 to May 2019 were reviewed. Only patients with combined positron‐emission tomography and computed tomography (PET/CT) scans consistent with radiologic stage I NSCLC were included. Identified variables included: age, gender, personal history of any cancer, smoking history, tumor location, tumor centrality, tumor size, tumor PET activity, histopathologic type of NSCLC, and LN biopsy results. Patients whose LN samples showed a diagnosis other than NSCLC were excluded. The association between LN positivity, and each of the variables was assessed using Pearson's correlation for categorical variables, and logistic regression analysis for continuous variables. Results From the 2,892 initially screened patients, 188 were included. Of those, 13 (6.9%; 95% CI, 4%–11%) had a malignancy‐positive LN biopsy. The number needed to test (NNT) in order to detect one case of any occult metastasis was 15. Among the included variables, a significant association was found between LN positivity and tumor centrality, with central tumors found in 61.5% of patients with positive LN (n = 8) (p