A definition problem in cancer metastasis.

Orthodox definitions of cancer metastasis state that deposits which qualify for this name are those found distant from the primary tumor. This qualification has led to considerable confusion in the literature. A study of the etymology and pathology of metastasis leads to the conclusion that the essential feature is transportation and not distance. Accordingly, metastasis should be defined simply as "the formation of another growth in any site following the transportation of tumor cells from the initial growth". This definition will probably improve knowledge of the statistics of cancer metastasis.