各种高等生物,如哺乳动物、鸡、蛙,甚至某些高等植物均可患肿瘤。肿瘤不是单一的疾病,而是一百多种疾病的总称,是一类细胞性的疾病。人体除毛发指甲外,均可患肿瘤。肺、乳腺以及其它组织中的肿瘤都可有多种不同的类型,它们的扩张能力、被机体免疫系统识别的难易以及对不同的治疗方式的反应均可有不同。细胞癌变最基本的特征是生长失控、迅速增殖、分化停止并恢 Various higher organisms, such as mammals, chickens, frogs, and even some higher plants, can develop tumors. Cancer is not a single disease, but it is a general term for more than one hundred diseases. It is a type of cellular disease. In addition to hair and nails, the human body can suffer from tumors. Tumors in the lungs, breasts, and other tissues can all have many different types. Their ability to expand, their ease of recognition by the body’s immune system, and their response to different treatments can vary. The most basic characteristic of cell cancerous transformation is uncontrolled growth, rapid proliferation, differentiation and recovery.