Gefitinib is mainly used in patients with EGFR19 gene deletion and 21 gene mutation in non-small cell lung cancer, which can significantly prolong the survival of patients, but there are some differences in how long different patients can live. The efficiency of oral gefitinib treatment can reach more than 70%. Currently, the overall survival time of patients with advanced lung adenocarcinoma treated with targeted drugs can reach 26-34 months, and some patients can even be treated for more than 5 years. However, if patients develop brain metastasis, the survival time may be 6-12 months. Generally, patients may experience adverse reactions such as diarrhea, rash, itching, dry skin and acne within 1 month of taking gefitinib, but they are usually reversible and can be treated symptomatically. In addition, lung cancer patients need to maintain a positive and optimistic attitude and cooperate with doctors for treatment in order to extend life and improve life quality in a more limited way.