There is no clear medical data on the cure rate of stage 3a lung adenocarcinoma after surgery, and generally the clinical five-year survival rate indirectly reflects the cure rate. Lung adenocarcinoma belongs to non-small cell lung cancer, and the five-year survival rate of stage 3a patients after surgery is about 20%~30%. Stage 3a lung adenocarcinoma belongs to locally advanced lung adenocarcinoma, the cancer foci have already spread to the surrounding tissues, but there is no distant metastasis. In order to improve the cure rate of the patients, radical surgery is still the main treatment means, but the patients need to have adjuvant chemotherapy to further reduce the recurrence rate of metastasis after the surgery, so as to enable the patients to have a longer period of survival. For patients who cannot be treated by surgical resection, the best way is to carry out simultaneous radiotherapy, 4-6 cycles of chemotherapy and local radiotherapy to prolong the survival of patients, or to carry out neoadjuvant chemotherapy before surgical resection. It is recommended that lung adenocarcinoma patients should go to regular hospitals for consultation and listen to the advice of professional doctors.