Interventional Procedures Section
Lung cancer is the leading cause of cancer-related deaths worldwide and forms of a large burden of cancer-related mortality in the United States. With the rapid advent of new disease-directed therapy, including molecular and targeted therapies, the outlook for management of lung cancer has changed dramatically over the last decade. The choice of therapy, as well as prognosis, is dependent on the stage at diagnosis. It is thus imperative that we accurately differentiate between stages I, II, and III disease by assessment of hilar and mediastinal lymph nodes.
Dr. Abhinav Agrawal
Traditionally, CT and PET/CT scans have been the mainstay to assess stage, with patients with abnormal lymph nodes or high risk of nodal metastasis (≥ T2 disease or “central” location) undergoing invasive mediastinal evaluation (Silvestri, et al. Chest. 2013 May;143(5 Suppl):e211S). The decision to perform invasive mediastinal staging for T1 tumors remains a matter of discussion. DuComb and colleagues, in their study demonstrated a high rate of N2 metastasis (8.1%) even amongst those with T1 tumors, which was independent of tumor location (DuComb, et al. Chest. 2020 Nov;158[5]:2192). This rate is consistent with previous reported rates ranging from 6.9% to 13% of N2 disease in patients with no radiographic evidence of lymph node metastasis (Gonzalez-Stawinski, et al. J Thorac Cardiovasc Surg. 2003 Dec;126[6]:1900; Bao, et al. J Thorac Dis. 2014;6[12]:1697; Shin, et al. Eur Respir J. 2019;53[3]:1801508). The above indicates a possible role of invasive mediastinal staging using EBUS-TBNA in patients with T1 disease to accurately stage the disease prior to curative intent treatment.
Dr. Ellen Volker
While the role of EBUS-TBNA in diagnosis and staging has been a role of ongoing research, data are limited on prognostic implications of EBUS-guided staging in patients with NSCLC. In a recently published paper in Chest, Hwangbo and colleagues assessed the prognostic impact of staging via EBUS in these patients (Hwangbo et al. Chest 2022 May;161[5]:1382). In the 1,089 patients who underwent EBUS-TBNA, they observed a significant difference in survival based on the staging established via EBUS-TBNA, highlighting the importance of EBUS-TBNA in staging for NSCLC. Also of note, patients with false-negative EBUS results had favorable survival that was similar to patients with pathologic N1 disease. While the exact reason for this is unclear and may be related to disease burden, the authors postulated that this may provide a rationale to performing surgery after negative EBUS-TBNA results.
Abhinav Agrawal, MD, FCCP, Member-at-Large
Ellen Volker, MD, MSPH, FCCP, Member-at-Large