In our mind, malignant tumor may be a kind of malignant disease that only old people in their old age will have. However, with the increase of clinical work, I found that more and more young people in their 20s and 30s are developing tumors, and the trend of cancer is happening at a younger age, a consensus that many oncologists may have a deep understanding of. The big data in the 2014 China Tumor Registry Annual Report also shows that the incidence of cancer in China shows a trend of rejuvenation, and often these young patients are in more serious condition and have worse prognosis than older patients with similar tumors. 1.Why cancer is getting younger and younger The reasons for the rejuvenation of cancer patients in China are mainly divided into two aspects: intrinsic and extrinsic. The main extrinsic factor is the serious environmental pollution nowadays, especially the problem of PM2.5 in the air, which is one of the main reasons for the increase of lung cancer incidence and rejuvenation; in addition, the problem of food safety may also be a causative factor for the high incidence of cancer. The intrinsic factors mainly lie in the bad lifestyle such as smoking, alcohol consumption, unhealthy diet, obesity, as well as anxiety and depression caused by the ubiquitous mental stress in the work life of modern society. Therefore, we’d better develop healthy living habits to minimize the risk of tumor. 2.Tumors in young people should not be neglected In fact, there is no clear definition of young cancer patients, which usually refers to adults between 20-39 years old. Patients in this age group have a wide variety of malignant tumors, and can develop common tumors including those in children and adults, but also have certain characteristics. Among them, breast cancer, lymphoma, colon cancer, thyroid cancer, cervical cancer, and melanoma are the most common. Malignant tumors are easily overlooked in the young population and delay the diagnosis. The main reason may be that firstly, young people are generally healthier and in good physical condition, so they seldom go to hospitals for checkups. Secondly, young people are generally in a busy state, whether they go to school, get employed, or get married and have children are all top events, so they seldom can spare time to care about their health status. In addition, the economic situation of young people is generally poor, so they may be resistant and bored to go to the hospital for examination, which may delay the diagnosis and treatment of the disease. Although malignant tumor is not a common disease among young people, we should be alert to it, and the most effective way is to conduct regular self-examination and screening of tumor. For example, breast cancer, which is highly prevalent in young women, requires regular medical checkups after the age of 20, at least once every 3 years; while mammography is recommended after the age of 40; if the patient has a clear family history or high-risk factors, then the screening can be done earlier and more frequently. Of course, self-examination is also very important, such as breast self-examination for women and testicular self-examination for men, both of which can be done for skin self-examination. Generally speaking, the signs and symptoms of tumor in early stage are not specific and may be similar to some other common benign diseases. Therefore, we should be alert to some common symptoms of tumor, including: nodules, swelling or swelling in the neck, breast, testicles or other parts of the body; abnormal bleeding; persistent pain somewhere in the body; fever that lasts for a long time and has poor anti-inflammatory effect; sudden loss of appetite or weight loss; a new pigmented mole on the skin or a change in the size, color, or shape of an existing pigmented mole. Although many benign diseases can also cause the above symptoms, it is best to go to the hospital for regular consultation and treatment at this time.