癌症是当前危害人类生命健康最严重的疾病之一,也是当前最重大而需要迫切解决的医学问题之一。许多年来,世界各国的医学者对癌的发生,病因,以及宿主与癌症之间的相互关系作了很多的研究,这些研究的成果,是通过动物实验与临床观察来阐明的。虽然目前对肿瘤的确切病因并不完全了解,但已明确发现许多对癌瘤发生的有关因素,这些因素包括外因与内因 Cancer is currently one of the most serious diseases that endanger human life and health. It is also one of the most important and urgently needed medical problems. For many years, medical researchers around the world have conducted a lot of research on the relationship between cancer occurrence, etiology, and host and cancer. The results of these studies are clarified through animal experiments and clinical observations. Although the exact cause of the tumor is not completely understood at present, many factors have been clearly identified for the occurrence of cancer, including external and internal causes.