Stage I of the IV stages of lung cancer

Stage I is the first of the 4 stages of lung cancer. It is used to describe cancer that is localized. There is no cancer in any lymph nodes. Stage I can be divided into IA and IB. Stage IA means the tumor is the tumor is small (3cm or less across). Stage IB means the cancer is larger or that it is growing in the main airway of the lung. Stage IB includes cancers that have grown into the inner covering of the lung or caused a partial collapse of the affected lung.