Alexander P, Murphy P, Skipper D
CRC Medical Oncology Unit, Faculty of Medicine, Southampton General Hospital, UK.
Adv Exp Med Biol. 1988;233:245-51. doi: 10.1007/978-1-4899-5037-6_27.
Carcinoma and sarcoma after gaining access to the venous circulation are completely trapped in the organs of first encounter, i.e. the lung and vertebrae for cancers draining into the vena cava, or liver for tumours with portal drainage. Systemic dissemination of carcinomas and sarcomas derives from cancer growing in the lung and can be mimicked in experimental rats by injecting cancer cells intra-arterially via the left ventricle. These emboli are arrested in different tissues in proportion to the cardiac output they receive, but the probability of a cancer embolus introduced in this way causing a lesion varies by several orders of magnitude for different tissues. Traumatising tissues by procedures such as surgical incision of the abdomen, gut anastomosis, placing a stitch in the kidney or chemical or surgical partial hepatectomy, greatly enhances the likelihood that a cancer cell trapped in the tissues develops into a metastasis. While several factors contribute to making a wound a more favourable "soil" for metastasis a major mechanism is the release of growth factors from macrophages that have infiltrated the wound.
癌和肉瘤一旦进入静脉循环，就会完全滞留在首次遇到的器官中，即对于引流至腔静脉的癌症，是肺和椎骨；对于经门静脉引流的肿瘤，则是肝脏。癌和肉瘤的全身播散源于肺部生长的肿瘤，通过经左心室动脉内注射癌细胞，可在实验大鼠中模拟这种情况。这些栓子会根据所接受的心输出量，在不同组织中滞留，但以这种方式引入的癌栓在不同组织中导致病变的概率相差几个数量级。通过诸如腹部手术切口、肠道吻合术、肾脏缝合或化学或手术部分肝切除术等操作损伤组织，会大大增加滞留在组织中的癌细胞发展为转移瘤的可能性。虽然有几个因素使得伤口成为更有利于转移的“土壤”，但一个主要机制是浸润伤口的巨噬细胞释放生长因子。
