Probability of metastasis formation for tumours of pT2 and pT4-stage. Simulation results for the probability of metastasis formation as a function of maximal reachable tumour size b of the Gompertz function. Calculations are shown for dissemination of malignant cells from the primary proportional to V2/3 and V1/3; the MS-model is shown in the upper, the GDR-model in the lower part. For the V1/3 proportionalities models with artificial, but reasonable reduced growth of the metastases are included. The black and red dashed lines denote the Munich Cancer Registry probabilities for pT2 and pT4. The normalisation to 1.1% at pT1-stage (black line) was calculated for the entire interval [5⋅1010, 1013 cells] of maximal tumour sizes; only one typical curve is shown for each plot. For every data point the mean of 2000 randomized courses of disease, each based on integer-disseminated cells, was calculated.