The fluorescent cytoprint assay: a new approach to in vitro chemosensitivity testing.

Today's chemotherapy is protocol driven and based on regimens derived from extensive clinical trials. Often, several proven regimens are available for a particular cancer, and little more than cost restrictions direct the physician's choice of protocol. Unfortunately, all patients do not respond to all regimens. Initial effective therapy is essential for good cancer control and patient management. Therefore, a predictive in vitro chemosensitivity test would be valuable in selecting treatment for individual patients. The fluorescent cytoprint assay (FCA) is an in vitro chemosensitivity assay that tests tumor specimens maintained in microorgan culture. The FCA has an assay success rate of 94% or better for most solid tumor types and predictive accuracies of 86% and 91% for positive and negative clinical responses, respectively. This paper summarizes 6 years of experience with this assay, discusses its advantages as a reliable predictive assay, and defends its place in chemotherapy decisions for individual patients.