So far, there is no clear limit on the number of years of taking targeted drugs for lung cancer in both international and domestic treatment guidelines. It is generally believed that as long as the patient has good efficacy of oral targeted drugs and no significant drug resistance has developed, it is recommended to keep taking them. If serious side effects occur and the patient cannot tolerate them, the dose needs to be reduced, which will affect the efficacy more or less. If all the existing targeted drugs are resistant, we can see if immunotherapy or systemic chemotherapy can be used. In conclusion, there are many treatment options for lung adenocarcinoma, so do not limit yourself to targeted drugs alone, they are all very effective.