INTRODUCTION: The American Joint Committee on Cancer (AJCC) 8th edition TNM staging manual for non-small-cell lung cancer (NSCLC), derived from the International Association for the Study of Lung Cancer (IASLC) Staging Project, designates tumors with additional nodule(s) in the same lobe as T3. This study sought to externally validate IASLC results, which showed a trend in improved survival for such tumors but excluded treatment-based adjustment, by assessing whether these tumors have worse survival than T2b NSCLC.METHODS: Overall survival of patients with T2b-T3, N0-3, M0 NSCLC (satisfying a single T descriptor of "T2b" [>4cm but =5cm in greatest dimension], "T3-size" [>5cm but =7cm in greatest dimension] or "T3-Add" [additional nodule(s) in the same lobe]), according to the AJCC 8th edition, in the National Cancer Data Base (2010-2015) was evaluated using multivariable Cox proportional hazards modeling and propensity score matching.RESULTS: 31,563 patients with T2b-T3, N0-3, M0 NSCLC met the study inclusion criteria. In multivariable-adjusted analysis, T3-Add tumors had improved overall survival compared to T3-Size tumors (HR: 0.86, 95% CI: 0.82-0.89, p<0.001), and similar survival compared to T2b tumors (HR: 1.04, 95% CI: 0.97-1.12, p=0.28). A propensity score-matched analysis of 2,260 T3-Add and 2,260 T2b patients, well-balanced on 16 common prognostic covariates, including treatment type (surgery, chemotherapy and/or radiation), demonstrated similar 5-year survival (53.4% vs 52.3%, p=0.30).CONCLUSIONS: In this national analysis, T3-Add tumors had better survival than other T3 tumors and similar survival to T2b tumors. These findings may be taken into consideration for the AJCC 9th edition staging classifications.
View details for DOI 10.1016/j.jtho.2021.06.016
View details for PubMedID 34242788