Do Metastases Metastasize?

SummaryA study was undertaken to investigate the biologic potential of tumor cells shed from pulmonary metastases in the autogenous host. First, preferential metastasis of the 5th generation of a methyl-cholanthrene-induced tumor of syngenic C57BL mice to lung tissue was demonstrated by subcutaneous transplantation of organ fragments. In a second experiment lung was transplanted into animals with pulmonary metastases. No secondary metastases occurred. Since this tumor is highly immunogenic, it was hypothesized that tumor specific immunity perhaps facilitated by amputation of the primary may inhibit the growth of tumor-cells shed from pulmonary metastases even in sites of preferential metastases. In this immunogenic murine tumor system, metastases do not metastasize.