Lung cancer 3 cm lymphatic metastasis is more serious, indicating that the patient has entered the middle stage of lung cancer. If the treatment is not timely, it will jeopardize the safety of life. Lymphatic metastasis of lung cancer 3cm indicates that the cancer cells have spread further and the condition is more serious. If the cancer cells have only metastasized to the lymph nodes near the lung gate and the metastasis is in a single site, the patient can undergo combined treatment through lesion excision surgery and lymph node dissection surgery, which has a certain chance of curing the disease. If the cancer cells have metastasized to multiple lymph nodes, the disease is more difficult to be cured and the prognosis is worse. Combined treatments such as surgery, chemotherapy and radiotherapy can be used as prescribed by doctors. If the condition is not properly controlled and the cancer cells have spread to distant places, it means that the condition has entered the advanced stage. At this time, the functions of various tissues and organs of the patient’s body will be seriously reduced, and the safety of the patient’s life will also be threatened. It is recommended that lung cancer patients should go to the hospital for professional treatment as soon as possible after lymphatic metastasis of cancer cells occurs in their body, and should not delay their condition.