切断癌症与肥胖之间的必经之路

　　 ——肥胖人群患癌风险确实比较高，而且一旦被确诊会出现更差的预后效果，并产生化疗耐药性，那么问题来了，这是为什么呢？

生物通报道：肥胖症的流行速度令人震惊，在世界范围内，估计有22亿成人属于超重或肥胖的范畴，其中许多都出现了代谢综合征的症状：血压升高和高水平血糖和胆固醇，还有循环胰岛素水平增加，炎性细胞因子增多等等。这些代谢和免疫的变化虽然本身已经成为了一种问题，但这并不是肥胖人口所面临的唯一的健康问题——肥胖会增加多种慢性疾病的患病风险和恶化风险，其中包括多种类型的癌症。今年，肥胖已经超越吸烟，成为了美国癌症死亡的首要因素。

问题一：肥胖和癌症存在什么关联？

近年来关于肥胖与癌症的研究都集中在预防癌症的行为干预方面了，但是对于全球将近7亿的肥胖成人来说，除了减肥植物，更有效的措施是减轻他们患病风险，美国临床肿瘤学会，世界癌症研究基金会等组织指出，肥胖相关的癌症就会是下个十年，癌症研究领域最为紧迫的问题。

（有十种类型的癌症与超重或肥胖有关，不仅肥胖会增加癌症的患病风险，而且这也是存活率降低，预后差，更快转移的一个诱导因素）

（胰岛素抵抗：许多肥胖患者都会出现胰岛素抵抗，而追踪激素的增多，也会促进癌症的发生，以及化疗耐药性的发生）

（细胞信号：介导相邻细胞之间的信号通路被干扰，这也会促进肿瘤发生和发展）

（活性脂肪：在肥胖患者体内肿瘤微环境中的脂肪细胞更为活跃，能分泌多种促癌激素和细胞因子）

（炎症：与肥胖有关的代谢变化也会刺激巨噬细胞生成过量的促炎症化合物，从而促进癌症发展，或通过诱发DNA损伤，抑制细胞凋亡，刺激细胞迁移和侵袭，来诱发癌症）

（肠道微生物组: 肥胖会导致肠道细菌多样性减少，损伤肠道屏障功能，令譬如脂多糖 (LPS)之类的细菌化合物渗漏到肠道之外。这又会进一步增加炎症，并促进癌症发展。）

 

下篇：

 下个十年，癌症研究最为紧迫是肥胖问题

原文文献：

Breaking the Cancer-Obesity Link（来自http://www.the-scientist.com/）

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