To determine whether lung cancer is early stage or not, it is mainly based on the size of lung cancer tumor, whether there is metastasis in regional lymph nodes and whether there is distant metastasis. If it is early stage lung cancer, there must be no metastasis in regional lymph nodes and distant places. It also depends on the size of the primary tumor. Early stage lung cancer tumor size is ≤7cm, and if the tumor size is >7cm, it is definitely not early stage. If the tumor invades the main bronchus, it needs to be ≥2cm from the rung, if it is <2cm from the rung, it is also not in the early stage. Invasion of pleura can only invade the dirty pleura, if it invades the wall pleura, it is not early stage. Pneumonia or obstructive pneumonia should not be a total pneumonia or atelectasis, and if it is a total pneumonia or atelectasis, it is not in the early stage.