Surgery is the standard treatment for early stage lung cancer, and on the whole, the earlier the staging, the better the effect; the later the staging, the greater the probability of recurrence and metastasis. However, there are some patients who have recurrence and metastasis at very early stage, what factors need special attention? 1. Tumor size: Tumor size is one of the most basic and important indexes in tumor staging. Early lung cancer can be divided into IA stage and IB stage according to its size, and IA stage can be divided into IA1, IA2, and IA3. The larger the lump is, the higher the chance of recurrence and metastasis. For example, in IB stage lung cancer, the tumor size is 3-5cm, which is relatively large, and the probability of recurrence is higher. Degree of differentiation The degree of differentiation is simply divided into high, medium and low differentiation, and for lung adenocarcinoma, it includes 5 pathological types, which are wall-adherent type, vesicular type, papillary type, solid type and micropapillary type. Adnexal type is highly differentiated, alveolar and papillary types are moderately differentiated, and solid and micropapillary types are poorly differentiated, and are the pathologic subtypes with the highest risk of recurrence. Especially, micropapillary type is considered to be the biggest indicator of poor prognosis, which is often prone to extensive lymphatic embolism when the primary lesion is very small, and is more likely to have early distant metastasis. 3. Pleural invasion According to TNM staging, no matter how small the lesion is, as long as there is pleural invasion, it belongs to stage IB, and pleural invasion is a high-risk factor for recurrence and metastasis of lung cancer, because it may be difficult to remove the cancer cells on the pleura during the surgery, and it may become the seed of recurrence. When it is not completely sure whether there is really invasion of the pleura in the visceral layer, elastic fiber staining is needed to determine it. 4.Ki-67 expression Positive Ki-67 expression indicates that cell proliferation is relatively active. Ki-67, also known as proliferation index, represents the active degree of cell proliferation. Generally speaking, the higher the positive rate of Ki-67, the more active cell proliferation, the higher the malignancy, and the more likely to invasion, recurrence and metastasis. If the Ki-67 positivity rate is low, for example, Ki-67 positivity rate <15%, it means that the cell proliferation is not active, it is not easy to have recurrence and metastasis, and the degree of malignancy will be relatively low. In the clinic, the degree of malignancy of the tumor will be judged according to the level of Ki-67 positive rate, so as to judge the risk of recurrence. 5. Whether there is intra-air cavity spread Intra-air cavity spread, or STAS for short, refers to the presence of tumor cells in the surrounding alveolar cavities of lung cancer other than the lesion, which is a kind of spreading mode of lung cancer newly confirmed by WHO in 2015.STAS affects the prognosis of patients with Stage IA lung cancer, and the prognosis of postoperative Stage IA lung cancer accompanied by STAS is similar to that of Stage IB. For early stage lung cancer with STAS, lobectomy rather than segmental resection is strongly recommended. 6. Whether there is any cancer thrombus in the vasculature Seeing cancer thrombus in the vasculature means that the cancer cells have entered the blood circulation. Even for early stage lung cancer accompanied by cancer thrombus in the vasculature, there is a possibility of local recurrence or distant metastasis after surgery. Therefore, blood test for MRD (micro residual disease) is necessary for postoperative patients with early stage lung cancer with vascular cancer thrombus. Among the genes of lung cancer, TP53 and/or KRAS gene mutation is an independent poor prognostic factor for early stage lung adenocarcinoma patients after surgery, especially for patients with invasive adenocarcinoma with solid growth as the main type, the P53 and/or KRAS mutation predicts a higher risk of recurrence and metastasis. The susceptibility of lung cancer to recurrence or metastasis after surgery is often accompanied by multiple factors working together. For patients with high risk factors, enhanced follow-up after surgery and timely treatment when recurrence or metastasis is detected are still very meaningful for the overall control of lung cancer and prolongation of survival.