Optimal prescription method for cancer chemotherapy.

A reexamination of the guidelines for prescriptions for cancer chemotherapy suggests that the use of body surface area (BSA) offers a simplification that may be open to some question. The same drug dose per BSA will give approximately the same toxicity in different age groups and species. This simplification appears to be fortuitous, however, as BSA does not correlate with the dose-limiting target cells, i.e., the hemopoietic stem cell. In patients with an unmodified hemopoietic system, body weight correlates significantly with hemopoietic stem cell concentration. It can be shown that changing the prescription unit from BSA to kilogram (kg) could lead to safer doses in children and neonates. In general, because of low therapeutic index, the expression of cancer chemotherapy drugs per dose-limiting normal tissue target cells could lead to safer and more effective cancer chemotherapy. New assays for prospective in vitro enumeration of dose-limiting target cells need to be developed. The indiscriminate use of BSA as a drug dose unit is discouraged.