Metastasis formation: number of colonies and metastatic tumour mass. Total amount of metastatic cells as well as total number of 1st and 2nd order colonies. The blue filled symbols represent the GDR-model, the open red stand for the MS-model. The growth function of the primary is also shown; an excision immediately after diagnosis would lead to a decrease of the amount of metastatic cells by 2 decades (dashed-dotted lines). Around day 1300 the amount of metastatic cells equals the primary, two years later the hundred fold is reached and latest from now the 2nd order metastases would dominate the course of disease.