Pharmacology of antineoplastic agents in older cancer patients
Clinical Trials as Topic
Persons over the age of 65 years are the fastest growing segment of the United States population. In the next 30 years this segment will comprise more than 20% of the population. Fifty percent of all cancers occur in this age group and therefore there will be an expected rise in the total cancer burden. Data is becoming available that will better guide the use of chemotherapy in the older patient population. Studies will be presented discussing pharmacokinetic data on several chemotherapeutic agents with an emphasis on those that have entered practice over the past few years. Many of these agents seem to have a beneficial therapeutic index, particularly for elderly patients. There has also been an increasing trend towards the use of oral chemotherapy. This change has been encouraged by the need to decrease the costs of chemotherapy administration, patient preferences, and quality of life issues. Factors that must be considered with oral chemotherapy administration include limitations of saturability of absorption, patient compliance and the pharmacokinetic and pharmacodynamic changes that occur in elderly patients. Interpatient variability and drug metabolism, particularly age-related changes in drug metabolism, have been studied. The cytochrome P450 system is particularly important. Careful attention to the physiologic changes with age and dose adjustments necessary for end organ dysfunction (renal, hepatic) is needed to ensure the safe administration of chemotherapy.