科学工作者为弄清肿瘤的病因发病机理,寻找有效的根治方法,先后建立过不少假说,对探讨肿瘤的病因发病机理、设计各种治疗方案,起着十分重要的作用。早在1775年,英国人珀西瓦尔、波特发现扫烟囱的工人易发生阴囊皮肤癌。1914年,日本人山极和市川用沥青长期涂抹兔耳两侧,成功地诱发了皮肤癌。首次证实了化学物质的致癌作用。以后, In order to understand the etiology and pathogenesis of tumors and to find effective cure methods, scientists have successively established a number of hypotheses and played an important role in exploring the etiology and pathogenesis of tumors and designing various treatment options. As early as 1775, British Percival, Porter found that chimney sweepers were prone to scrotal skin cancer. In 1914, the Japanese people, Yamachi and Ichikawa, applied asphalt on both sides of rabbit ears for a long time and successfully induced skin cancer. For the first time, the carcinogenic effects of chemicals have been confirmed. after,