Stage 1a invasive lung adenocarcinoma refers to lung cancer with tumor less than or equal to 3cm, without lymphatic and distant metastasis, and with cancer cells breaking through the basement membrane and originating from glandular epithelium. Lung cancer is also known as primary bronchial lung cancer, which can be categorized into small cell lung cancer, squamous lung cancer, adenocarcinoma of lung, etc. according to the different cells of origin of cancer cells. Among them, adenocarcinoma is one of the most common types of lung cancer, which is most common in women and mainly originates from bronchial mucous glands. According to the degree of invasion of cancer cells, it can be categorized into carcinoma in situ (non-invasive carcinoma) and invasive carcinoma. Carcinoma in situ means that the cancer cells are confined within the epithelium and have not broken through the basement membrane. Invasive carcinoma refers to cancer cells invading the basement membrane and infiltrating deeper tissues. Stage 1a invasive lung adenocarcinoma is an earlier lung cancer, and patients are advised to seek timely medical treatment so as not to miss the disease.