Validation of the lung cancer staging system revisions using a large prospective clinical trial database (ACOSOG Z0030).

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7021 Background: A new revision of the international lung cancer staging system has been recently introduced. The revisions are largely focused on the T descriptor. We sought to test the validity of this new system on a separate prospectively collected cohort of patients from a recent multicenter trial of early-stage lung cancer. Methods: We reviewed the prospectively collected data from 1,087 patients undergoing pulmonary resection for lung cancer in the ACOSOG Z0030 trial. TNM descriptors and overall staging were assessed using both the 6th and 7th editions of the AJCC/UICC lung cancer staging system. Survival results were analyzed according to both staging allocations. Results: The number of patients by stage in the 6th and 7th edition allocations respectively were as follows: IA (454, 453); IB (417, 314); IIA (42, 180); IIB (107, 75); IIIA (44, 64); IIIB (23,1); there were no stage IV patients by either version. Overall survival comparisons are provided in the Table. Conclusions: This study provides the first external validation of the recently revised lung cancer staging system using a large multicenter database. Inasmuch as its revisions concentrate predominantly on the T descriptor, the 7th edition does produce prognostic results that demonstrate monotonic progression, distinction between groups, and homogeneity within groups. The 7th edition of the AJCC/UICC lung cancer staging system appears to be an improvement over the preceding system. 6th edition T/N stage Median survival (yrs) 5-year survival (%) p value* T1 NA 73.5 - T2 6.9 59.1 <0.0001 T3 2.6 24.3 0.0002 T4 2.4 44.4 0.5232 N0 8.7 68.2 - N1 4.0 43.3 <0.0001 N2 2.7 36.1 0.6881 IA NA 76.0 - IB 7.9 62.9 <0.0001 IIA 3.9 46.1 0.0181 IIB 3.9 41.2 0.7026 IIIA 1.8 28.0 0.2678 IIIB 2.4 44.4 0.4806 7th edition T/N stage T1 NA 74.4 - T1a NA 75.4 - T1b 9.1 73.1 0.3896 T2 6.9 59.2 - T2a 6.9 61.2 0.0058 T2b 5.1 51.1 0.0631 T3 3.0 39.6 0.2088 T4 1.4 - 0.0041 N0 8.7 68.2 - N1 4.0 43.3 <0.0001 N2 2.7 36.1 0.6881 IA NA 77.0 - IB 8.5 64.9 0.0002 IIA 4.4 48.5 0.0003 IIB 3.6 42.9 0.4668 IIIA 1.8 30.6 0.1203 T1 vs. T2, p value < 0.0001 T2 vs. T3, p value = 0.0021 T3 vs. T4, p value = 0.0041. * Stage groups were consecutively compared (i.e., IA vs. IB, IB vs. IIA, etc.). No significant financial relationships to disclose.