A GENERALIZED TUMOR-GROWTH DELAY ASSAY FOR QUANTIFYING ALTERATIONS OFTUMOR REGROWTH PATTERNS

Tumor growth delay (TGD) is a widely accepted method for in situ asses sment of tumor treatment modalities. However, it has some drawbacks: ( 1) dependency on arbitrary endpoints and, even more serious, (2) lack of alterations of the tumor - growth pattern after treatment. In the p resent study a generalization of TGD is proposed which is based on the analysis of tumor growth curves by applying the difference equation-o f the Gompertz function. The advantages of the present method consist primarily of addressing the drawbacks of the classical assay mentioned above: generalized TGD permits a quantitative evaluation of treatment -induced alterations of tumor-growth patterns after treatment as well as estimations of TGD in a classical form by comparing growth curves a s entities, i.e. independently of endpoints. The possibility of studyi ng dose-effect relationships of antineoplastic treatment modalities by the generalized TGD is demonstrated by applying this method on experi mental chemotherapy and radiotherapy data.