Validation of IASLC Classification for Nodal ECE of Tumor

Feb 14, 2024

Photo Credit: Dr. Microbe

The following is a summary of “Validation of the Proposed International Association for the Study of Lung Cancer Residual Tumor Classification to Upgrade Extracapsular Extension of Tumor in Nodes From R0 to Incomplete Resection,” published in the January 2024 issue of Oncology by Xie et al.

The International Association for the Study of Lung Cancer (IASLC) suggested a new R classification that would move tumors in lymph nodes from R0 to R1 based on their extracapsular extension (ECE). Still, more information is needed to support this plan.

For a study, researchers sought to compare patients with ECE to those with R0, R(un), and partial resection (R1 and R2); overall survival (OS) was looked at after reclassification by IASLC-R. The pattern of ECE return was looked at to see if it was linked to partial removal. There were 1,136 people with N disease. About 4061 surgery patients with NSCLC were part of the study.

Those who did not have ECE (n = 754, 67%) had a significantly better OS than those who did have ECE (n = 382, 33%) (P< 0.001). This bad predictive meaning was the same in several different categories. The results of the multivariate analysis showed that ECE was a risk factor that could be used on its own (P < 0.001). When patients with ECE were taken out of the IASLC-R1 group, their OS was much worse than that of IASLC-R(un) patients. However, it was about the same as the remaining IASLC-R1 patients’ OS when all patients and patients with N disease were looked at together.

Also, people who had ECE had a higher chance of local recurrence in the mediastinum (P < 0.001), ipsilateral lung (P = 0.031), and malignant pleural effusion or nodes (P = 0.004), but not of distant recurrence in the liver (P = 0.728), brain (P = 0.252), bone (P = 0.322), or ipsilateral or contralateral lungs (P= 0.268). The outlook for ECE patients is about the same as for R1 patients. In addition, their higher risk of local return suggests that there are still tumor cells in the surgery hemithoracic cavity that haven’t been seen. As a result, it makes sense to move ECE to partial removal.