Hypothesis: Cancer alloustasis

Despite decades of study, there are still many unanswered questions about cancer metastasis. One of these questions is about the origin of the tumor cells that give rise to metastases. The currently accepted models of cancer metastasis are inconsistent with some clinical observations of the natural history of cancer and its response to therapy, challenging our understanding of the nature of metastasis. Here, we coin a term ‘cancer alloustasis’ to describe the tumor that forms de novo in secondary sites, but is not originated from primary site derived cells. Moreover, we present a complementary hypothesis suggesting that the progenitors of alloustasis are distinct with those of primary tumors and the outgrowth of alloustases is promoted by primary tumors.