Fifteen year olds can get cancer, such as some hereditary tumors (nephroblastoma) or tumors common in adolescents (leukemia). Hereditary malignancies are also a group of malignancies to which children and adolescents are susceptible, such as nephroblastoma, dyschromia, Fanconi anemia, familial breast cancer, familial retinoblastoma, and familial polyposis adenomatosa. There are some tumors that are not hereditary but often occur in children and adolescents, such as osteosarcoma, embryonal tumors, and leukemia. Most of the malignant tumors in adolescents are sarcomas, such as sarcomas of bone, soft tissue and lymphohematopoietic system. Cancer growth is not regulated by the normal body and destroys normal tissues and organs. There are many causative factors of cancer, such as the molecular mechanisms of tumorigenesis. Cell growth is controlled by many regulatory factors, especially growth factors. Oncogene activation (point mutation, gene amplification), loss of function of oncogenes, etc. Environmental factors are also important in carcinogenesis, such as ammonium nitrites, fungal substances, and carcinogenic aromatic amines. Finally, there are genetic factors. The role of genetic factors in tumors is to increase the patient’s susceptibility to a particular tumor. So 15-year-old children are also at risk of cancer, if there are symptoms, it is recommended that timely hospital consultation, early diagnosis and early treatment to achieve the best therapeutic effect.