Metastasis progression is a clonally selective process on whole-body level

There is an argument about the metastatic progression. Not even one model can perfectly interpret the new results in cancer metastasis research. Cancer cells spread early from the primary site and give rise to metastasis. Logically, cancer cells may depart from the metastatic site early and reseed into the primary cancer. If the cells can migrate between the primary cite and the metastatic sites, plus adequate time, finally the clone with most selective advantage would dominate the primary and metastatic sites. Therefore, we surmise that the metastasis progression is a clonally selective process on whole-body level. Therapeutic attempts to better control cancer metastasis should therefore consider the interaction of primary and metastatic cancer.