A method of fitting non-symmetric Gompertz functions for characterising malignant growth

A basic symmetrically asymptotic Gompertz equation was extended to account for more complex growth and life-table data. This extended Gompertz or non-symmetric asymptotic regression equation was found to be suitable for fitting a large variety of data exhibiting growth and experimentally-induced regression effects expressed in the same curve. The statistical and computational properties of this fitting function are discussed in theory and example.