Lung cancer is a very common malignant tumor of the respiratory system. If you are completely unable to eat and drink only water in the late stage, you will definitely not have a long survival time, usually about a week to a month. If intravenous nutritional support is available and some nutrient solution is given, the survival time may be longer. However, it can only be seen while treatment. The treatment of advanced lung cancer is mainly palliative and symptomatic, and pain relief treatment. Generally speaking, if there are mutations in advanced lung cancer, targeted drug therapy can still prolong survival, such as the commonly used targeted drugs for lung cancer, Trokai and Erysal, which can be used for lung cancer patients with advanced lung adenocarcinoma and EGFR gene mutation. For others who cannot apply targeted therapy, they can also try radiotherapy and chemotherapy, which, if effective, can also reduce patients’ pain and prolong their survival a little.