Abstract
Purpose This study aimed to investigate the application of the number of positive lymph nodes (PLNs) in tumor, node, metastasis (TNM) staging system of non-small cell lung cancer (NSCLC) patients. Patients and Methods. We screened a total of 15820 patients with resected NSCLC between 2004 and 2015 from SEER database. The X-tile model was used to determine the cutoff values of the number of PLNs. Overall survival (OS) curves were plotted using the Kaplan–Meier method, and the differences among the individual groups were defined using the log-rank test. Cox regression model was used to perform univariate and multivariate analyses and to assess the association between the number of PLNs and OS. Results In this study, using the X-tile model, we screened three different cutoff values, including nN0, nN1–3, and nN4-. Survival curves demonstrated that our defined nN stage had a significant predictive value for OS (P < 0.001). In the univariate and multivariate Cox analyses, the result showed that nN stage was a significant prognostic factor of OS for NSCLC patients (P < 0.001). Subsequently, we classified the patients into five subgroups based on the combination of pN and nN stages, including pN0 + nN0, pN1 + nN1-3, pN2 + nN1-3, pN1 + nN4-, and pN2 + nN4-. Moreover, survival curves revealed significant differences among these five groups (P < 0.001). Conclusion A combination of pathological LNs (pN) and the number of LN (nN) involvement in NSCLC patients had a better prognostic value than the current TNM staging system based on only pN stage.
Highlights
Lung cancer is considered a severe disease worldwide and is the leading cause of cancer death, where 85% comprises non-small cell lung cancer (NSCLC) [1, 2]
E tumor, node, metastasis (TNM) staging system, based on primary tumor character (T), nodal involvement (N), and distant metastasis (M), has a significant impact on therapeutic options and prognosis, which is essential in determining ways to deliver care to patients. ere were some updates of T and M classification in the eighth version, but the N classification remained unchanged [4, 5]
A total of 65.1% of patients belonged to the nN0 stage, and 23.2% and 11.7% patients were in stage nN1-3 and stage nN4, respectively
Summary
Lung cancer is considered a severe disease worldwide and is the leading cause of cancer death, where 85% comprises non-small cell lung cancer (NSCLC) [1, 2]. Us, accurate staging, proper treatment, Journal of Oncology and better prognosis are essential to improve the survival of NSCLC patients [3]. E tumor, node, metastasis (TNM) staging system, based on primary tumor character (T), nodal involvement (N), and distant metastasis (M), has a significant impact on therapeutic options and prognosis, which is essential in determining ways to deliver care to patients. Since pathologically positive lymph node (PLN) indicates a higher recurrence risk, accurate assessment of LN is essential in creating treatment strategy and prognostic care. Even lymphadenectomy is recommended to be performed in lung resection surgery to ensure a significant survival, but still, 25% to 50% of early-stage lung cancer patients have a disease recurrence, suggesting that the current staging system is still inaccurately sufficient to assess NSCLC. LN stations were elaborated in the latest 8th edition of the TNM staging system, with no more details about the exact number in the classification
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
