NCIt definition : Stage IIIA includes: T3, N0, M0. T3: Tumor with direct invasion into any of the following:
lung, brachiocephalic vein, superior vena cava, phrenic nerve, chest wall, or extrapericardial
pulmonary artery or veins. N0: No regional lymph node metastasis. M0: No distant metastasis.
(AJCC 8th ed.);