The most important factors affecting the recurrence and prognosis of lung cancer are tumor size and mediastinal lymph node metastasis, in addition, stage is also an important factor. The 5-year local recurrence rate of lung cancer has been reported to be 6% 10% for stage i, 25% 35% for stage i, and 45% 75% for stage a; the incidence of distant metastases is about 20% in stage i and may be as high as 67% in stage a. The 5-year survival rates for n1 and n2 lung cancer do not exceed 35% and 13%, and because of the different survival rates for stage a patients, there have been recent reports of dividing n2 patients into different subgroups. In a retrospective study, andre et al. found that patients with a clinical diagnosis of n2 based on preoperative ct scan had a lower 5-year survival rate than patients with a negative ct scan and a histopathological diagnosis of n2. The number of mediastinal lymph node metastases and the number of metastatic groups are two other important factors that affect the prognosis of lung cancer. Therefore, intraoperative clearance of lymph nodes and their grouping are essential. Currently, there is no consensus on the most appropriate surgical step. Although many studies have shown that certain genetic markers are significantly associated with lung cancer prognosis, no multifactorial analysis of large samples has demonstrated that any of these markers are independent prognostic indicators or have predictive value for adjuvant treatment response. However, all of this information can help physicians decide which patients are likely to benefit from adjuvant therapy, and the administration of adjuvant therapy can help kill occult metastatic lesions and prevent recurrence even in early-stage lung cancers that can be completely resected. Thoracic radiotherapy is controversial in adjuvant therapy, especially in patients without mediastinal lymph node metastases . Since more than 70% of recurrences occur outside the thoracic cavity, the implementation of chemotherapy becomes an important reason. However, chemotherapy is not considered the standard of care because the results of randomized clinical trials comparing postoperative adjuvant chemotherapy with single surgery are not yet consistent. 1995 meta-analysis showed that cisplatin-based chemotherapy may have an impact on survival after radical resection, followed by clinical trials with newer and less toxic drugs. Chemotherapy plus radiotherapy is a new treatment paradigm performed in recent years to improve local control and reduce distant metastases.