Additional lymph node evaluation needed during surgery to accurately identify lung cancer spread

Breakthrough research presented at the 2026 Society of Thoracic Surgeons Annual Meeting shows that additional lymph node evaluation is needed during surgery for non-small cell lung cancer (NSCLC) to accurately identify cancer spread.

Globally, surgical standards vary on the number and location of lymph nodes that should be removed and assessed for metastasis in patients with clinically node-negative NSCLC, cancer that imaging shows has not spread. In North America, surgical standards developed in 2021 call for assessment of three N2 nodes in the mediastinum between the right and left lungs, and one N1 node in the root of the lung.

The study recommends that more than one N1 node be removed and evaluated. Using data from the STS General Thoracic Surgery Database (GTSD), the largest clinical thoracic surgical database in North America with nearly 800,000 procedure records and more than 900 participating surgeons, the study found that more cancers were identified in N1 than N2 nodes, with many located in N1 nodes adjacent to the bronchi.

We are narrowing down the best techniques for lymph node dissections in patients with lung cancer to give the best chance of identifying any cancer that is there and improving survival."

Christopher Seder, MD, study author, thoracic surgeon at Rush University Medical Center, Chicago

The study is based on the review of 48,779 clinically node-negative patients with NSCLC and found that 11.2% were upstaged following surgery - meaning that surgical dissection of their lymph nodes revealed their cancers were more advanced than originally thought and reclassified at high stages. Patients underwent wedge resection, segmentectomy, or lobectomy. Patients were treated between July 2021 and 2024 across 279 centers and identified from the GTSD. Patients who received neoadjuvant therapy, received a preoperative mediastinoscopy, lacked preoperative PET-CT imaging, or had incomplete pathologic data were excluded.

"With expanded node dissection, more patients whose cancer has spread will be identified, and they will receive appropriate systemic treatments," Seder added.

"The onus here is not only on surgeons for them to dissect more lymph nodes, but on pathologists to take the lung specimen we give them and do a very thorough evaluation of that lung specimen to get all the additional lymph nodes with cancer that are hiding in the specimen," said Seder.

Surgeons often encounter complex decisions about which lymph nodes to remove. These new findings offer valuable insights that can help inform future updates to lymph node dissection guidelines.

The GTSD, part of the STS National Database, is a true national benchmark, capturing detailed information on patient characteristics, surgical procedures, and outcomes. This study highlights the value of large-scale, real-world data analysis in informing clinical practice and guiding patient care.