People of any age may suffer from tumors, and for most malignant tumors, the risk of tumor occurrence increases with age. The age incidence curves of malignant tumors in each area show that they have their own characteristics, such as esophageal cancer, gastric cancer, lung cancer, etc., which are tumors with significant effects of external factors and are subject to their effects throughout human life, thus the curves continue to rise with age. The highest incidence of malignant tumors in general is seen in people aged 55-70. In recent years, the age of incidence of some tumors has been decreasing, i.e., the trend is younger. Breast cancer, gastric cancer, lung cancer are no longer exclusively developed by the elderly, and the younger the age of some tumor patients, the greater the deterioration of the tumor. The proportion of tumor mortality in the total human mortality also has a tendency to increase significantly with age. In China, for example, tumor mortality is lowest in the age group of 5-14 years. The rate of tumor mortality increases with age, and is fastest between 35 and 39 years of age, decreasing slightly after 75 years of age for men, but continuing to increase for women. As mentioned earlier, the overall morbidity and mortality of tumors generally increases with age, but there are two special cases. One special case is that the incidence of tumors in children, 0-5 years old, is higher than that of children in the 5-15 years old age group, and childhood leukemia and embryonic malignancies, such as retinoblastoma and nephroblastoma, mostly occur before the age of 5 years, which may be due to the fact that the immune mechanism in childhood is not yet sound, leading to an increased incidence. This may be due to the fact that the incidence rate increases during childhood when the immune mechanism is not yet complete, and decreases with the growth of the immune level; another difference is that after the age of 70-75, although the incidence rate of splenoma continues to increase, the proportion of tumor death in the total death tends to decrease. This is because the threat of cardiovascular and cerebrovascular diseases to the life of the elderly increases with age, so much so that it exceeds the threat of tumors. In addition, the types of tumors that are good for people at different ages are different. Take our statistics as an example, leukemia, followed by brain tumor and malignant lymphoma, are the most common tumors that die in adolescence (O-14 years old); liver cancer and leukemia are the most common in youth (15-35 years old); tumors of stomach, esophagus, cervix, liver and lung are the most common in prime age (35-55 years old) and old age (after 55 years old). Because of this, age is often used as one of the main reference factors when considering risk factors for certain tumors. For example, in addition to family history and reproductive history, age over 35 years, especially over 50 years, is also considered as a risk factor for breast cancer.