When cancer is advanced and terminal, it may lead to respiratory failure and the inability to breathe. It suggests that there may be cancer cell lung metastasis or invasion of trachea or bronchus or something like that. There is no good way to treat the disease, you can consider applying oxygen and wheezing drugs to relieve the symptoms. If the patient is physically able to tolerate anti-tumor treatment, radiotherapy can be done to control the development of lung metastasis. It may also be able to relieve the situation of breathlessness. Advanced cancer may also be accompanied by other inflammatory lung lesions, such as obstructive pneumonia. Anti-inflammatory, asthma, cough and phlegm medicines can be applied to relieve the symptoms. In addition, if advanced cancer is accompanied by more pleural effusion, thoracentesis and fluid extraction can also relieve the symptoms of dyspnea.