The logarithm of tumour volume vs. time for all metastases in the liver (A) and lungs (B), with corresponding exponential growth fit to each metastasis. SGR is given for each tumour; the values in parentheses for each line depict the doubling time in months. A trend of decreasing growth rate (slope of line) from large to small tumours is visible for liver metastases, but not for lung metastases. C The best exponential (dashed line) and Gompertzian (solid line) model curve fits to the logarithm of the volume of liver metastasis A with extrapolation to the volume of one cell. b represents the birth of the patient.