New TNM classification of malignant lung tumours

The staging system for lung tumours is now recommended for the classification of both non-small-cell and small-cell lung cancer as well as for carcinoid tumours of the lung. The T classifications have been redefined: T1 has been subclassified as T1a (a parts per thousand currency sign2 cm in size) and T1b (> 2-3 cm in size). T2 has been subclassified as T2a (> 3-5 cm in size) and T2b (> 5-7 cm in size). T2 (> 7 cm in size) has been reclassified as T3. Multiple tumour nodules in the same lobe have been reclassified from T4 to T3. Multiple tumour nodules in the same lung but a different lobe have been reclassified from M1 to T4. No changes have been made in the N classification. The M classification has been redefined: M1 has been subdivided into M1a and M1b. Malignant pleural and pericardial effusions have been reclassified from T4 to M1a. Separate tumour nodules in the contralateral lung have been reclassified from T4 to M1a. M1b designates distant metastasis.