《The Emperor of All Maladies: A

But cancer is not simply a clonal disease; it is a clonally evolving disease. If growth occurred without evolution, cancer cells would not be imbued with their potent capacity to invade, survive, and metastasize. Every generation of cancer cells creates a small number of cells that is genetically different from its parents. When a chemotherapeutic drug or the immune system attacks cancer, mutant clones that can resist the attack grow out. The fittest cancer cell survives. This mirthless, relentless cycle of mutation, selection, and overgrowth generates cells that are more and more adapted to survival and growth. In some cases, the mutations speed up the acquisition of other mutations. The genetic instability, like a perfect madness, only provides more impetus to generate mutant clones. Cancer thus exploits the fundamental logic of evolution unlike any other illness. If we, as a species, are the ultimate product of Darwinian selection, then so, too, is this incredible disease that lurks inside us.

• evolve /iˈvɑːlv/ v. 进化；演化
• evolution /ˌiːvəˈluːʃn/ n. 演变; 进化; 发展
• imbue /ɪmˈbjuː/ ~ sb/sth (with sth): to fill sb/sth with strong feelings, opinions or values 使充满，灌输，激发（强烈感情、想法或价值）
• potent /ˈpoʊtnt/ adj. having a strong effect on your body or mind 有强效的；有力的；烈性的；影响身心的
• invade /ɪnˈveɪd/ v. 侵犯；（尤指造成损害或混乱地）涌入；侵袭
• metastasize /məˈtæstəˌsaɪz/ v. 转移；迁徙
• chemotherapeutic /ˌkiːmoʊˈθerəpi/ n. the treatment of disease, especially cancer, with the use of chemical substances （尤指对癌的）化学治疗，化学疗法，化疗
• immune /ɪˈmjuːn/ adj. 有免疫力的；
  immune system 免疫系统
• relentless /rɪˈlentləs/ adj. 残酷的, 不留情的, 无怜悯心的
• fundamental /ˌfʌndəˈmentl/
  adj. serious and very important; affecting the most central and important parts of sth 十分重大的；根本的
  n. a basic rule or principle; an essential part 基本规律；根本法则；基本原理；基础
• ultimate /ˈʌltɪmət/
  adj. happening at the end of a long process 最后的；最终的；终极的
  n. the best, most advanced, greatest, etc. of its kind 最好（或先进、伟大等）的事物；极品；精华
• lurk /lɜːrk/ v. 尤指为做不正当的事而）埋伏，潜伏；不好或危险的事）潜在，隐藏着

但是癌症不仅仅是一种克隆性疾病，而是一种伴随着进化的克隆性疾病。如果只是生长而没有进化，癌细胞就不会充满强大的入侵、生存和转移的能力。每一代癌细胞都会产生少量在基因上不同于上一代的细胞。当化疗药物或者免疫系统攻击癌细胞的时候，变异的癌细胞就能抵抗住攻击并生存发展下去，也就是适者生存。这种残酷无情的变异、选择和过度生长不断循环，进化出越来越适应生存和生长的癌细胞。在某些情况下，这些突变会加速其他突变的产生。遗传的不稳定性，就像一种完美的疯狂，为突变的产生提供了更多的动力。因此，不同于任何其他疾病，癌症利用了进化的基本逻辑。如果我们人类作为一个物种是达尔文进化论的最终产物，那么潜伏在我们体内的这种令人难以置信的疾病也是如此。