Weiss L
Invasion Metastasis. 1983;3(4):193-207.
Basically two hypotheses can be used to account for the metastatic inefficiency of cancer cells. The first is that the inefficiency is apparent, and reflects the small proportions of cells of a preexisting metastatic phenotype in primary tumors which are available for metastasis; thus, metastasis and metastatic inefficiency result from nonrandom processes. The opposed view is that most cancer cells have metastatic potential which is not realized unless they randomly enter a transient metastatic compartment which increases their chances of random survival in the metastatic cascade; thus, metastasis and metastatic inefficiency are basically random events. Discussion of this issue has been confused by the indisputable existence of cancer cell heterogeneity and cell lines with 'high' and 'low' metastatic or metastasis-related behavior. However, the relationship of these lines to naturally occurring metastasis is not at all clear. The evidence suggests that metastasis and metastatic inefficiency are determined by a series of random events, and although the presence of metastatic variants could alter the rate or efficiency with which metastasis occurs, they are not expected to determine whether they occur or not, or to produce major modifications in either.
基本上有两种假说可用于解释癌细胞转移效率低下的现象。第一种假说是，这种低效率是表面的，反映了原发性肿瘤中具有预先存在的转移表型、可供转移的细胞比例较小；因此，转移和转移低效率是由非随机过程导致的。相反的观点是，大多数癌细胞具有转移潜能，除非它们随机进入一个短暂的转移区室，增加其在转移级联中随机存活的机会，否则这种潜能无法实现；因此，转移和转移低效率基本上是随机事件。癌细胞异质性以及具有“高”和“低”转移或转移相关行为的细胞系的无可争议的存在，使得对这个问题的讨论变得混乱。然而，这些细胞系与自然发生的转移之间的关系根本不清楚。证据表明，转移和转移低效率是由一系列随机事件决定的，虽然转移变体的存在可能会改变转移发生的速率或效率，但它们预计不会决定转移是否发生，也不会对两者产生重大改变。
