Stage 2b lung adenocarcinoma is an early stage, including T2bN1M0 and T3N0M0, and surgical treatment is chosen first, with 4 cycles of adjuvant chemotherapy after surgery for complete resection. Postoperative radiotherapy does not affect the survival of patients, although it increases the local control rate. A meta-analysis showed that postoperative radiotherapy may increase the risk of death in stage 2 and is therefore not recommended as routine treatment. Radiation therapy can be done for those who do not have standardized mediastinal lymph node dissection, those with extra-peripheral lymph node invasion, those with extensive metastases in hilar lymph nodes, and those with close incisional margins.