Abstract
Determinants of host—drug interaction comprise a complex of potentially variable factors. The complexity of this variability compromises the forecasting of favorable response in individual patients given standard therapy. Substantial success with current forms of chemotherapy may require that biochemical, pharmacologic, and clinical profiles be established for each cancer patient whereby the use of drug and drug combination can be rationally applied. The significance of evaluating clinical pharmacokinetic parameters in patients with cancer is placed in perspective with other factors relevant to individual drug response.