ABSTRACT
This chapter addresses an important question concerning the xenograft, namely, the comparison of tumor response to chemotherapy in the nude mouse system and in the patient. The screening program of the National Cancer Institute (NCI) has utilized three human tumor models for the secondary screening from 1975 to 1985. Most of the antitumor agents used in patients were initially selected for their activity in a variety of animal tumor models. Since the human tumor xenograft model has demonstrated a highly correct prediction for tumor sensitivity and resistance, it might be used as a model for identifying drugs active against an individual patient's tumor. The number of xenografts necessary for a particular tumor type depends mainly on the individual pattern of tumor response. H. M. Pinedo has proposed to use four to five human tumor xenografts for the initial screening of new compounds.
