Since the latest revision of the TNM system reclassified T3N0 tumours into the Ⅱ B stage, N2 lesions became the major determinant of the Ⅲ A stage. Concing the minority of patients with T3N1 tumours in this stage, their prognosis depends on characteristic of T3 tumours: loealised chest wall invasion is associated with more favourable prognosis compared to those T3 tumours that either directly invade the mediastinum, or have the proximal propagation < 2 cm from the central carina.