Lung Cancer Staging Non-small Cell If you like this animation, LIKE us on Facebook: This 3D medical animation begins with a detailed description of the staging or progression of the lung cancer. It describes the occult stage where cancer cells are in the body fluid but no tumor can be seen in the lungs. Stage 0 occurs when cancer cells are found in the airway lining. It goes to demonstrate Stage IA, IB, IIA, IIB which are considered invasive and the cancer cells have invaded the airway lining. ANS00402