Adenocarcinoma is a malignant tumor from glandular epithelium, the specific symptoms and prognosis are closely related to the site of onset, stage, etc., and it is usually considered as a serious disease. 1. Breast cancer: over-nutrition, high-fat diet, excessive drinking, etc. can increase the chance of the disease. Some patients will have lumps in the breasts, and the breast skin will be dimpled and orange peel-like. According to some studies, the 1-year, 3-year and 5-year survival rates are 87.9%, 53.8% and 41.8% respectively. 2. Lung adenocarcinoma: Smoking, long-term exposure to chemical pollutants and ionizing radiation are the causes of lung adenocarcinoma. In early stage, there are no obvious symptoms, but in late stage, it can be manifested as obvious emaciation, fatigue, hemoptysis and other symptoms. As lung adenocarcinoma is easy to metastasize in the early stage, most of the patients are already in the advanced stage when diagnosed, therefore, the prognosis is poor, and the average 5-year survival rate is less than 20%. 3. Prostate cancer: it is common in old men, usually related to obesity, high-fat diet, heredity and other factors. It usually has no obvious symptoms in the early stage, and in the late stage, there will be difficulty in urination and other phenomena. Domestic research says that the survival rate of 1, 5 and 10 years is 72.57%, 38.08% and 18.57% respectively. In conclusion, adenocarcinoma belongs to malignant tumors, it is recommended to go to regular hospitals for active diagnosis and evaluation of the condition, and treat according to the situation in order to improve the prognosis and quality of life.