Lung nodule 3cm is not necessarily early stage lung cancer. In addition to early lung cancer, 3cm nodules in the lungs may also be caused by other diseases, such as pneumonia, tuberculosis, lung calcification foci, etc., all of which may appear as lung nodules, and these diseases are not related to early lung cancer. A 3cm nodule in the lung cannot be completely ruled out as lung cancer. At present, the nodule is 3cm, the diameter is larger, and the chance of malignant tumor is higher. If it is related to lung cancer, the patient will also have symptoms such as coughing, coughing up sputum, body weakness, hemoptysis and so on. However, besides early lung cancer, there is also the possibility of mid-stage or late lung cancer, so you cannot judge whether it is early lung cancer based on lung nodules alone. If you want to accurately analyze whether lung nodules are related to lung cancer, you should do pathological examination and tumor markers as soon as possible to analyze the cause of the disease and then standardize the treatment.