Pharmacology of aging and cancer: how useful are pharmacokinetic tests?

The elderly comprise the majority of patients with cancer and are the recipients of the greatest amount of chemotherapy. Unfortunately, there is a lack of data to make evidence-based decisions with regard to chemotherapy. This is due to the minimal participation of older patients in clinical trials and that trials have not systematically evaluated chemotherapy. This chapter reviews the available information with regard to chemotherapy and aging. Due to the lack of prospective data, the conclusions and recommendations made are a consensus of the available information. Extrapolation of data from younger to older patients is necessary, particularly to those patients older than 80 years, for which data is almost entirely lacking. The classes of drugs reviewed include alkylators, antimetabolites, platinum compounds, anthracyclines, taxanes, purine analogues, antimicrotubule agents, camptothecins, and epipodophyllotoxins. Clinical trials need to incorporate an analysis of chemotherapy in terms of the pharmacokinetic and pharmacodynamic effects of aging. In addition, data already accumulated need to be re-analyzed by age to aid in the management of the older cancer patient.