Table 1. Stage Grouping Comparisons: Sixth Edition Versus Seventh Edition Descriptors, T and M Categories, and Stage Groupingsa,b
| Sixth Edition T/M Descriptor (cm) | Seventh Edition T/M | N0 | N1 | N2 | N3 |
| T1 (≤2) | T1a | IA | IIA | IIIA | IIIB |
| T1 (>2–3) | T1b | IA | IIA | IIIA | IIIB |
| T2 (≤5) | T2a | IB | IIA | IIIA | IIIB |
| T2 (>5–7) | T2b | IIA | IIB | IIIA | IIIB |
| T2 (>7) | T3 | IIB | IIIA | IIIA | IIIB |
| T3 invasion | T3 | IIB | IIIA | IIIA | IIIB |
| T4 (same lobe nodules) | T3 | IIB | IIIA | IIIA | IIIB |
| T4 (extension) | T4 | IIIA | IIIA | IIIB | IIIB |
| M1 (ipsilateral lung) | T4 | IIIA | IIIA | IIIB | IIIB |
| T4 (pleural effusion) | M1a | IV | IV | IV | IV |
| M1 (contralateral lung) | M1a | IV | IV | IV | IV |
| M1 (distant) | M1b | IV | IV | IV | IV |
| T = primary tumor; N0 = no regional lymph node metastasis; N1 = metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension; N2 = metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s); N3 = metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node(s); M = distant metastasis. |
| aCells in bold indicate a change from the sixth edition for a particular TNM category. |
| bReprinted with permission from Goldstraw P, Crowley J, Chansky K, et al.: The IASLC Lung Cancer Staging Project: Proposals for the revision of the TNM stage groupings in the forthcoming (seventh) edition of the TNM classification of malignant tumours. J. Thorac Oncol 2:706-14, 2007. |
