Patients with advanced lung cancer suddenly get better, and after treatment, some patients will have this situation, especially patients with advanced lung adenocarcinoma, who have genetic mutations, can be treated with targeted drugs, and there is an intermediate period of time when the patient’s condition gradually improves, symptoms gradually remit, and there is no time of disease progression. Some patients with positive ALK mutations can achieve a median disease-free survival of more than 18 months and an overall survival of 34.2 months after treatment with the targeted drug aletinib. During such a long period of time, the patient’s symptoms may be relatively mild, the symptoms caused by the tumor will gradually remit, and the patient will feel a remission of the disease. However, after targeted therapeutic drugs and chemotherapy treatment, there will be cases of drug resistance or disease progression again eventually. In this case, it is necessary to change the treatment plan or decide the next treatment according to the re-examination.