Metastasis from the Brain.

The present investigation was undertaken to determine whether the failure of brain tumors to metastasize was related to local conditions at the site of origin. Three hamster tumors and two rabbit tumors, known to be capable of metastasis, were trans planted to the brains of animals of the same species. The tumors grew rapidly but killed the bearers before sufficient time had elapsed to allow the formation of metastatic growths. Accordingly, tissues of the tumor-bearing animals were transplanted homologously to normal adult animals to provide additional time for contained tumor cells, if present, to manifest themselves by growth. Tumor growth occurred in tissue transplants in all five instances, and it was concluded that conditions peculiar to the brain were not operative in the failure of brain tumors to metastasize.