Clinical method to estimate time of origin and maximum volume of malignant tumors.
The purpose of this study is to investigate a method to obtain the magnitude of growth parameters in the Gompertzian function growth model and to extrapolate this function forwards and backwards by applying the parameters. Non exponential linearity of malignant tumors has been reported and experimental and clinical evidence of growth limitation even in malignant tissues has also been detected. In clinical practices the conventional exponential growth model is often insufficient. So we applied the Gompertzian function to infer growth patterns using the parameters obtained from breast carcinoma skin metastases and from leiomyosarcoma lung metastases. We found that breast carcinoma grows faster but its growth rate retards more quickly, whereas the leiomyosarcoma grows slowly but its growth rate hardly regresses. Interesting results are obtained extrapolating this function forwards and backwards using the parameters. As a consequence the retardation factor becomes more important than the growth rate.