肿瘤的病因及发病学: 过去将肿瘤病因分为物理的,化学的、生物的等等。现在,特别在第十二届国际肿瘤会议上认为肿瘤病因70—90％为环境因素,其它为遗传因素。在环境因素方面又以化学因素为主。早在1775年,就发现扫烟囱的工人发生阴囊皮肤癌,从而证实化学物质的致癌作用。近年来,组织化学方法有了很大发展,特别是显微组织化学随着生化方法的进展,而能更多地显示出组织和细胞内离子、蛋白质、脂肪、碳水化合物及酶等各种物质。 The etiology and pathogenesis of cancer: In the past, the etiology of cancer was divided into physical, chemical, biological, and so on. Now, at the 12th International Conference on Tumors, 70-90% of the etiology of cancer is considered as an environmental factor, and other factors are genetic factors. In terms of environmental factors, it is mainly based on chemical factors. As early as 1775, it was discovered that workers who had chimney sweeps developed scrotal skin cancer, thus confirming the carcinogenic effects of chemicals. In recent years, the histochemical methods have been greatly developed, especially with the progress of biochemical methods in microscopic histochemistry, which can more show various substances such as ions, proteins, fats, carbohydrates and enzymes in tissues and cells. .