[Thoughts on a mathematical understanding of the growth of experimental tumors]

A contribution by Krug and Taubert concerning the mathematical approximation of Ehrlich ascites tumor growth using logit transformation of the logistic function followed by an approximation of the prefinal decline of the cell number gives rise to further contemplations. The authors aimed at a rather simple method to be realised with programmable pocket computers. A proposal offered by Dr. Krug lead the author to further investigations into the problem in question. As one possibility the sigmoidal function is replaced by a special form of the Janoschek function whilst the multiplicative descending exponential function mainly responsible for the prefinal stage is given a more flexible character. As a result the ascending phase is only slightly altered whereas the stage of decline shows different behaviour partly due to the few and scattering input data for this branch of the growth curve. By this method linear deviations are reduced by about a quarter in the example treated.